From 68aebc1b56bee1d433cd8faf2790209e9da6c11e Mon Sep 17 00:00:00 2001
From: "github-actions[bot]"
 <41898282+github-actions[bot]@users.noreply.github.com>
Date: Thu, 18 Aug 2022 08:00:14 -0400
Subject: [PATCH] [release/7.0-rc1] Fix nullable annotations on generic math
 interfaces (#74116)

* Fix nullable annotations on generic math interfaces

- All `where TSelf : ...` constraints become `where TSelf : ...?`.  Without this, trying to define a type like `Matrix<T> where T : INumber<T>?` in order to support nullable T types warns because `INumber<T>` constrains its `T` (`TSelf`) to be non-nullable.
- All `where TOther : ...` constraints are changed to be oblivious. They can't be correctly annotated as there's no way to express the nullability relationship with the nullability of TSelf.
- Use `[MaybeNullWhen(false)] out T` instead of `[NotNullWhen(true)] out T?`, as we do with other generics, since if the instantiation of `T` is nullable, we can't guarantee `NotNullWhen(true)`.
- Make `IEqualityOperators` `==` and `!=` accept `TSelf?`. This keeps it consistent with `IEquatable<T>.Equals(T?)`, `IEqualityComparer<in T>.Equals(T?, T?)`, `IEqualityComparer.Equals(object?, object?)`, `IStructuralEquatable.Equals(object?, IEqualityComparer)`, and `object.Equals(object?)` which all allow null even if generic and the generic is non-null. It in turn enables checks like `T.Zero == default` without nullability warnings.

* Address PR feedback

Co-authored-by: Stephen Toub <stoub@microsoft.com>
---
 .../System.Private.CoreLib/src/System/Byte.cs |  12 +-
 .../System.Private.CoreLib/src/System/Char.cs |  12 +-
 .../Collections/Concurrent/ConcurrentQueue.cs |   2 +-
 .../src/System/Collections/Generic/Queue.cs   |   4 +-
 .../src/System/Decimal.cs                     |  12 +-
 .../src/System/Double.cs                      |  12 +-
 .../System.Private.CoreLib/src/System/Half.cs |  12 +-
 .../src/System/IParsable.cs                   |   2 +-
 .../src/System/ISpanParsable.cs               |   2 +-
 .../src/System/Int128.cs                      |  12 +-
 .../src/System/Int16.cs                       |  12 +-
 .../src/System/Int32.cs                       |  12 +-
 .../src/System/Int64.cs                       |  12 +-
 .../src/System/IntPtr.cs                      |  12 +-
 .../src/System/Numerics/IAdditionOperators.cs |   2 +-
 .../src/System/Numerics/IAdditiveIdentity.cs  |   2 +-
 .../Numerics/IBinaryFloatingPointIeee754.cs   |   2 +-
 .../src/System/Numerics/IBinaryInteger.cs     |  23 +-
 .../src/System/Numerics/IBinaryNumber.cs      |   2 +-
 .../src/System/Numerics/IBitwiseOperators.cs  |   2 +-
 .../System/Numerics/IComparisonOperators.cs   |   2 +-
 .../System/Numerics/IDecrementOperators.cs    |   2 +-
 .../src/System/Numerics/IDivisionOperators.cs |   2 +-
 .../src/System/Numerics/IEqualityOperators.cs |   6 +-
 .../System/Numerics/IExponentialFunctions.cs  |   2 +-
 .../src/System/Numerics/IFloatingPoint.cs     |   2 +-
 .../Numerics/IFloatingPointConstants.cs       |   2 +-
 .../System/Numerics/IFloatingPointIeee754.cs  |   2 +-
 .../System/Numerics/IHyperbolicFunctions.cs   |   2 +-
 .../System/Numerics/IIncrementOperators.cs    |   2 +-
 .../System/Numerics/ILogarithmicFunctions.cs  |   2 +-
 .../src/System/Numerics/IMinMaxValue.cs       |   2 +-
 .../src/System/Numerics/IModulusOperators.cs  |   2 +-
 .../Numerics/IMultiplicativeIdentity.cs       |   2 +-
 .../src/System/Numerics/IMultiplyOperators.cs |   2 +-
 .../src/System/Numerics/INumber.cs            |   2 +-
 .../src/System/Numerics/INumberBase.cs        |  38 ++-
 .../src/System/Numerics/IPowerFunctions.cs    |   2 +-
 .../src/System/Numerics/IRootFunctions.cs     |   2 +-
 .../src/System/Numerics/IShiftOperators.cs    |   2 +-
 .../src/System/Numerics/ISignedNumber.cs      |   2 +-
 .../System/Numerics/ISubtractionOperators.cs  |   2 +-
 .../Numerics/ITrigonometricFunctions.cs       |   2 +-
 .../Numerics/IUnaryNegationOperators.cs       |   2 +-
 .../System/Numerics/IUnaryPlusOperators.cs    |   2 +-
 .../src/System/Numerics/IUnsignedNumber.cs    |   2 +-
 .../System/Runtime/InteropServices/NFloat.cs  |  14 +-
 .../src/System/SByte.cs                       |  12 +-
 .../src/System/Single.cs                      |  12 +-
 .../src/System/UInt128.cs                     |  12 +-
 .../src/System/UInt16.cs                      |  12 +-
 .../src/System/UInt32.cs                      |  12 +-
 .../src/System/UInt64.cs                      |  12 +-
 .../src/System/UIntPtr.cs                     |  12 +-
 .../ref/System.Runtime.InteropServices.cs     |   6 +-
 .../ref/System.Runtime.Numerics.cs            |  12 +-
 .../src/System/Numerics/BigInteger.cs         |  12 +-
 .../src/System/Numerics/Complex.cs            |  12 +-
 .../System.Runtime/ref/System.Runtime.cs      | 219 ++++++++++--------
 .../System/Numerics/GenericMathDimHelpers.cs  |   6 +-
 60 files changed, 340 insertions(+), 280 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Byte.cs b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
index 6541d1a1f8cf0..2a45415301196 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Byte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
@@ -920,7 +920,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out byte resu
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<byte>.TryConvertToChecked<TOther>(byte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<byte>.TryConvertToChecked<TOther>(byte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -987,14 +987,14 @@ static bool INumberBase<byte>.TryConvertToChecked<TOther>(byte value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<byte>.TryConvertToSaturating<TOther>(byte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<byte>.TryConvertToSaturating<TOther>(byte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1061,14 +1061,14 @@ static bool INumberBase<byte>.TryConvertToSaturating<TOther>(byte value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<byte>.TryConvertToTruncating<TOther>(byte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<byte>.TryConvertToTruncating<TOther>(byte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1135,7 +1135,7 @@ static bool INumberBase<byte>.TryConvertToTruncating<TOther>(byte value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Char.cs b/src/libraries/System.Private.CoreLib/src/System/Char.cs
index b93226bb9778e..d506f503d48be 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Char.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Char.cs
@@ -1715,7 +1715,7 @@ static bool INumberBase<char>.TryConvertFromTruncating<TOther>(TOther value, out
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<char>.TryConvertToChecked<TOther>(char value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<char>.TryConvertToChecked<TOther>(char value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1782,14 +1782,14 @@ static bool INumberBase<char>.TryConvertToChecked<TOther>(char value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<char>.TryConvertToSaturating<TOther>(char value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<char>.TryConvertToSaturating<TOther>(char value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1856,14 +1856,14 @@ static bool INumberBase<char>.TryConvertToSaturating<TOther>(char value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<char>.TryConvertToTruncating<TOther>(char value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<char>.TryConvertToTruncating<TOther>(char value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1930,7 +1930,7 @@ static bool INumberBase<char>.TryConvertToTruncating<TOther>(char value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Collections/Concurrent/ConcurrentQueue.cs b/src/libraries/System.Private.CoreLib/src/System/Collections/Concurrent/ConcurrentQueue.cs
index 7a49887d17c28..3fa2f71ade78f 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Collections/Concurrent/ConcurrentQueue.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Collections/Concurrent/ConcurrentQueue.cs
@@ -683,7 +683,7 @@ public bool TryDequeue([MaybeNullWhen(false)] out T result)
             // check and this check, another item could have arrived).
             if (head._nextSegment == null)
             {
-                result = default!;
+                result = default;
                 return false;
             }
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Queue.cs b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Queue.cs
index e9f9f6c307f98..7a793902166a0 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Queue.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/Queue.cs
@@ -231,7 +231,7 @@ public bool TryDequeue([MaybeNullWhen(false)] out T result)
 
             if (_size == 0)
             {
-                result = default!;
+                result = default;
                 return false;
             }
 
@@ -263,7 +263,7 @@ public bool TryPeek([MaybeNullWhen(false)] out T result)
         {
             if (_size == 0)
             {
-                result = default!;
+                result = default;
                 return false;
             }
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
index 5436baebfdc57..8b469e385b13d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
@@ -1645,7 +1645,7 @@ private static bool TryConvertFrom<TOther>(TOther value, out decimal result)
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<decimal>.TryConvertToChecked<TOther>(decimal value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<decimal>.TryConvertToChecked<TOther>(decimal value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1712,26 +1712,26 @@ static bool INumberBase<decimal>.TryConvertToChecked<TOther>(decimal value, [Not
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<decimal>.TryConvertToSaturating<TOther>(decimal value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<decimal>.TryConvertToSaturating<TOther>(decimal value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<decimal>.TryConvertToTruncating<TOther>(decimal value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<decimal>.TryConvertToTruncating<TOther>(decimal value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
-        private static bool TryConvertTo<TOther>(decimal value, [NotNullWhen(true)] out TOther result)
+        private static bool TryConvertTo<TOther>(decimal value, [MaybeNullWhen(false)] out TOther result)
             where TOther : INumberBase<TOther>
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
@@ -1804,7 +1804,7 @@ private static bool TryConvertTo<TOther>(decimal value, [NotNullWhen(true)] out
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Double.cs b/src/libraries/System.Private.CoreLib/src/System/Double.cs
index 177eb912575ed..75580d6a88c8b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Double.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Double.cs
@@ -1243,7 +1243,7 @@ private static bool TryConvertFrom<TOther>(TOther value, out double result)
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<double>.TryConvertToChecked<TOther>(double value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<double>.TryConvertToChecked<TOther>(double value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1304,26 +1304,26 @@ static bool INumberBase<double>.TryConvertToChecked<TOther>(double value, [NotNu
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<double>.TryConvertToSaturating<TOther>(double value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<double>.TryConvertToSaturating<TOther>(double value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<double>.TryConvertToTruncating<TOther>(double value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<double>.TryConvertToTruncating<TOther>(double value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
-        private static bool TryConvertTo<TOther>(double value, [NotNullWhen(true)] out TOther result)
+        private static bool TryConvertTo<TOther>(double value, [MaybeNullWhen(false)] out TOther result)
             where TOther : INumberBase<TOther>
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
@@ -1402,7 +1402,7 @@ private static bool TryConvertTo<TOther>(double value, [NotNullWhen(true)] out T
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Half.cs b/src/libraries/System.Private.CoreLib/src/System/Half.cs
index ba931c1f93cec..ecab10dbc00d6 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Half.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Half.cs
@@ -1727,7 +1727,7 @@ private static bool TryConvertFrom<TOther>(TOther value, out Half result)
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Half>.TryConvertToChecked<TOther>(Half value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Half>.TryConvertToChecked<TOther>(Half value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1788,26 +1788,26 @@ static bool INumberBase<Half>.TryConvertToChecked<TOther>(Half value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Half>.TryConvertToSaturating<TOther>(Half value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Half>.TryConvertToSaturating<TOther>(Half value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Half>.TryConvertToTruncating<TOther>(Half value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Half>.TryConvertToTruncating<TOther>(Half value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
-        private static bool TryConvertTo<TOther>(Half value, [NotNullWhen(true)] out TOther result)
+        private static bool TryConvertTo<TOther>(Half value, [MaybeNullWhen(false)] out TOther result)
             where TOther : INumberBase<TOther>
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
@@ -1879,7 +1879,7 @@ private static bool TryConvertTo<TOther>(Half value, [NotNullWhen(true)] out TOt
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/IParsable.cs b/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
index af220483d640e..e2891fbd68947 100644
--- a/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/IParsable.cs
@@ -8,7 +8,7 @@ namespace System
     /// <summary>Defines a mechanism for parsing a string to a value.</summary>
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IParsable<TSelf>
-        where TSelf : IParsable<TSelf>
+        where TSelf : IParsable<TSelf>?
     {
         /// <summary>Parses a string into a value.</summary>
         /// <param name="s">The string to parse.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs b/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
index 8ad117cfa4c6e..2e24d5173e2fb 100644
--- a/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/ISpanParsable.cs
@@ -8,7 +8,7 @@ namespace System
     /// <summary>Defines a mechanism for parsing a span of characters to a value.</summary>
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface ISpanParsable<TSelf> : IParsable<TSelf>
-        where TSelf : ISpanParsable<TSelf>
+        where TSelf : ISpanParsable<TSelf>?
     {
         /// <summary>Parses a span of characters into a value.</summary>
         /// <param name="s">The span of characters to parse.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int128.cs b/src/libraries/System.Private.CoreLib/src/System/Int128.cs
index b67d6e89a7006..d66655060f3e1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int128.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int128.cs
@@ -1865,7 +1865,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out Int128 re
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Int128>.TryConvertToChecked<TOther>(Int128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Int128>.TryConvertToChecked<TOther>(Int128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1926,14 +1926,14 @@ static bool INumberBase<Int128>.TryConvertToChecked<TOther>(Int128 value, [NotNu
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Int128>.TryConvertToSaturating<TOther>(Int128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Int128>.TryConvertToSaturating<TOther>(Int128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -2000,14 +2000,14 @@ static bool INumberBase<Int128>.TryConvertToSaturating<TOther>(Int128 value, [No
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Int128>.TryConvertToTruncating<TOther>(Int128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Int128>.TryConvertToTruncating<TOther>(Int128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -2069,7 +2069,7 @@ static bool INumberBase<Int128>.TryConvertToTruncating<TOther>(Int128 value, [No
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int16.cs b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
index a357d272360fa..94fe0e4844f08 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
@@ -1148,7 +1148,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out short res
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<short>.TryConvertToChecked<TOther>(short value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<short>.TryConvertToChecked<TOther>(short value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1209,14 +1209,14 @@ static bool INumberBase<short>.TryConvertToChecked<TOther>(short value, [NotNull
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<short>.TryConvertToSaturating<TOther>(short value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<short>.TryConvertToSaturating<TOther>(short value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1278,14 +1278,14 @@ static bool INumberBase<short>.TryConvertToSaturating<TOther>(short value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<short>.TryConvertToTruncating<TOther>(short value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<short>.TryConvertToTruncating<TOther>(short value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1346,7 +1346,7 @@ static bool INumberBase<short>.TryConvertToTruncating<TOther>(short value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int32.cs b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
index 317c789c7d676..7b7c3f2765fb1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
@@ -1158,7 +1158,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out int resul
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<int>.TryConvertToChecked<TOther>(int value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<int>.TryConvertToChecked<TOther>(int value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1219,14 +1219,14 @@ static bool INumberBase<int>.TryConvertToChecked<TOther>(int value, [NotNullWhen
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<int>.TryConvertToSaturating<TOther>(int value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<int>.TryConvertToSaturating<TOther>(int value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1290,14 +1290,14 @@ static bool INumberBase<int>.TryConvertToSaturating<TOther>(int value, [NotNullW
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<int>.TryConvertToTruncating<TOther>(int value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<int>.TryConvertToTruncating<TOther>(int value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1358,7 +1358,7 @@ static bool INumberBase<int>.TryConvertToTruncating<TOther>(int value, [NotNullW
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int64.cs b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
index 569240329da35..8752d93c2f837 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
@@ -1143,7 +1143,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out long resu
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<long>.TryConvertToChecked<TOther>(long value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<long>.TryConvertToChecked<TOther>(long value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1204,14 +1204,14 @@ static bool INumberBase<long>.TryConvertToChecked<TOther>(long value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<long>.TryConvertToSaturating<TOther>(long value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<long>.TryConvertToSaturating<TOther>(long value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1283,14 +1283,14 @@ static bool INumberBase<long>.TryConvertToSaturating<TOther>(long value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<long>.TryConvertToTruncating<TOther>(long value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<long>.TryConvertToTruncating<TOther>(long value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1351,7 +1351,7 @@ static bool INumberBase<long>.TryConvertToTruncating<TOther>(long value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs b/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
index 9f6b414343b15..3fbed0cea3520 100644
--- a/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/IntPtr.cs
@@ -1117,7 +1117,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out nint resu
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nint>.TryConvertToChecked<TOther>(nint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nint>.TryConvertToChecked<TOther>(nint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1178,14 +1178,14 @@ static bool INumberBase<nint>.TryConvertToChecked<TOther>(nint value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nint>.TryConvertToSaturating<TOther>(nint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nint>.TryConvertToSaturating<TOther>(nint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1250,14 +1250,14 @@ static bool INumberBase<nint>.TryConvertToSaturating<TOther>(nint value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nint>.TryConvertToTruncating<TOther>(nint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nint>.TryConvertToTruncating<TOther>(nint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1318,7 +1318,7 @@ static bool INumberBase<nint>.TryConvertToTruncating<TOther>(nint value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditionOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditionOperators.cs
index ca11868381a29..ecdfe953a0c8c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditionOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditionOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will be added to <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that contains the sum of <typeparamref name="TSelf" /> and <typeparamref name="TOther" />.</typeparam>
     public interface IAdditionOperators<TSelf, TOther, TResult>
-        where TSelf : IAdditionOperators<TSelf, TOther, TResult>
+        where TSelf : IAdditionOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Adds two values together to compute their sum.</summary>
         /// <param name="left">The value to which <paramref name="right" /> is added.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditiveIdentity.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditiveIdentity.cs
index 1e95b5fb35cc8..be11ca7e2fbf7 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditiveIdentity.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IAdditiveIdentity.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     /// <typeparam name="TResult">The type that contains the additive identify of <typeparamref name="TSelf" />.</typeparam>
     public interface IAdditiveIdentity<TSelf, TResult>
-        where TSelf : IAdditiveIdentity<TSelf, TResult>
+        where TSelf : IAdditiveIdentity<TSelf, TResult>?
     {
         /// <summary>Gets the additive identity of the current type.</summary>
         static abstract TResult AdditiveIdentity { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryFloatingPointIeee754.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryFloatingPointIeee754.cs
index 7e6565579d4ff..151ae4c11d082 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryFloatingPointIeee754.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryFloatingPointIeee754.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     public interface IBinaryFloatingPointIeee754<TSelf>
         : IBinaryNumber<TSelf>,
           IFloatingPointIeee754<TSelf>
-        where TSelf : IBinaryFloatingPointIeee754<TSelf>
+        where TSelf : IBinaryFloatingPointIeee754<TSelf>?
     {
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryInteger.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryInteger.cs
index e182d35b04246..067d6c338384e 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryInteger.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryInteger.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     public interface IBinaryInteger<TSelf>
         : IBinaryNumber<TSelf>,
           IShiftOperators<TSelf, int, TSelf>
-        where TSelf : IBinaryInteger<TSelf>
+        where TSelf : IBinaryInteger<TSelf>?
     {
         /// <summary>Computes the quotient and remainder of two values.</summary>
         /// <param name="left">The value which <paramref name="right" /> divides.</param>
@@ -25,7 +25,12 @@ static virtual (TSelf Quotient, TSelf Remainder) DivRem(TSelf left, TSelf right)
         /// <returns>The number of leading zeros in <paramref name="value" />.</returns>
         static virtual TSelf LeadingZeroCount(TSelf value)
         {
-            TSelf bitCount = TSelf.CreateChecked(value.GetByteCount() * 8L);
+            if (!typeof(TSelf).IsValueType)
+            {
+                ArgumentNullException.ThrowIfNull(value);
+            }
+
+            TSelf bitCount = TSelf.CreateChecked(value!.GetByteCount() * 8L);
 
             if (value == TSelf.Zero)
             {
@@ -132,7 +137,12 @@ static virtual TSelf ReadLittleEndian(ReadOnlySpan<byte> source, bool isUnsigned
         /// <returns>The result of rotating <paramref name="value" /> left by <paramref name="rotateAmount" />.</returns>
         static virtual TSelf RotateLeft(TSelf value, int rotateAmount)
         {
-            int bitCount = checked(value.GetByteCount() * 8);
+            if (!typeof(TSelf).IsValueType)
+            {
+                ArgumentNullException.ThrowIfNull(value);
+            }
+
+            int bitCount = checked(value!.GetByteCount() * 8);
             return (value << rotateAmount) | (value >> (bitCount - rotateAmount));
         }
 
@@ -142,7 +152,12 @@ static virtual TSelf RotateLeft(TSelf value, int rotateAmount)
         /// <returns>The result of rotating <paramref name="value" /> right by <paramref name="rotateAmount" />.</returns>
         static virtual TSelf RotateRight(TSelf value, int rotateAmount)
         {
-            int bitCount = checked(value.GetByteCount() * 8);
+            if (!typeof(TSelf).IsValueType)
+            {
+                ArgumentNullException.ThrowIfNull(value);
+            }
+
+            int bitCount = checked(value!.GetByteCount() * 8);
             return (value >> rotateAmount) | (value << (bitCount - rotateAmount));
         }
 
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryNumber.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryNumber.cs
index 9b45fb59cc73b..5dbe5bc957609 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryNumber.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBinaryNumber.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     public interface IBinaryNumber<TSelf>
         : IBitwiseOperators<TSelf, TSelf, TSelf>,
           INumber<TSelf>
-        where TSelf : IBinaryNumber<TSelf>
+        where TSelf : IBinaryNumber<TSelf>?
     {
         /// <summary>Gets an instance of the binary type in which all bits are set.</summary>
         static virtual TSelf AllBitsSet => ~TSelf.Zero;
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBitwiseOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBitwiseOperators.cs
index 15a7aa311f642..36399a1b6d96c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IBitwiseOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IBitwiseOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will is used in the operation with <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that contains the result of <typeparamref name="TSelf" /> op <typeparamref name="TOther" />.</typeparam>
     public interface IBitwiseOperators<TSelf, TOther, TResult>
-        where TSelf : IBitwiseOperators<TSelf, TOther, TResult>
+        where TSelf : IBitwiseOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Computes the bitwise-and of two values.</summary>
         /// <param name="left">The value to and with <paramref name="right" />.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IComparisonOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IComparisonOperators.cs
index d6b8883aa718c..474ea46e7f656 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IComparisonOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IComparisonOperators.cs
@@ -9,7 +9,7 @@ namespace System.Numerics
     /// <typeparam name="TResult">The type that is returned as a result of the comparison.</typeparam>
     public interface IComparisonOperators<TSelf, TOther, TResult>
         : IEqualityOperators<TSelf, TOther, TResult>
-        where TSelf : IComparisonOperators<TSelf, TOther, TResult>
+        where TSelf : IComparisonOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Compares two values to determine which is less.</summary>
         /// <param name="left">The value to compare with <paramref name="right" />.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IDecrementOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IDecrementOperators.cs
index 159ad6bc44e2d..edc0022c58447 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IDecrementOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IDecrementOperators.cs
@@ -6,7 +6,7 @@ namespace System.Numerics
     /// <summary>Defines a mechanism for decrementing a given value.</summary>
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IDecrementOperators<TSelf>
-        where TSelf : IDecrementOperators<TSelf>
+        where TSelf : IDecrementOperators<TSelf>?
     {
         /// <summary>Decrements a value.</summary>
         /// <param name="value">The value to decrement.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IDivisionOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IDivisionOperators.cs
index a8ed07a633591..20535020efcd7 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IDivisionOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IDivisionOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will divide <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that contains the quotient of <typeparamref name="TSelf" /> and <typeparamref name="TOther" />.</typeparam>
     public interface IDivisionOperators<TSelf, TOther, TResult>
-        where TSelf : IDivisionOperators<TSelf, TOther, TResult>
+        where TSelf : IDivisionOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Divides two values together to compute their quotient.</summary>
         /// <param name="left">The value which <paramref name="right" /> divides.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IEqualityOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IEqualityOperators.cs
index 397e4489aefbe..ebf11d8576e4e 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IEqualityOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IEqualityOperators.cs
@@ -8,18 +8,18 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will be compared with <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that is returned as a result of the comparison.</typeparam>
     public interface IEqualityOperators<TSelf, TOther, TResult>
-        where TSelf : IEqualityOperators<TSelf, TOther, TResult>
+        where TSelf : IEqualityOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Compares two values to determine equality.</summary>
         /// <param name="left">The value to compare with <paramref name="right" />.</param>
         /// <param name="right">The value to compare with <paramref name="left" />.</param>
         /// <returns><c>true</c> if <paramref name="left" /> is equal to <paramref name="right" />; otherwise, <c>false</c>.</returns>
-        static abstract TResult operator ==(TSelf left, TOther right);
+        static abstract TResult operator ==(TSelf? left, TOther? right);
 
         /// <summary>Compares two values to determine inequality.</summary>
         /// <param name="left">The value to compare with <paramref name="right" />.</param>
         /// <param name="right">The value to compare with <paramref name="left" />.</param>
         /// <returns><c>true</c> if <paramref name="left" /> is not equal to <paramref name="right" />; otherwise, <c>false</c>.</returns>
-        static abstract TResult operator !=(TSelf left, TOther right);
+        static abstract TResult operator !=(TSelf? left, TOther? right);
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IExponentialFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IExponentialFunctions.cs
index 85660ab3ba3c8..f7370ff4708fb 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IExponentialFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IExponentialFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IExponentialFunctions<TSelf>
         : IFloatingPointConstants<TSelf>
-        where TSelf : IExponentialFunctions<TSelf>
+        where TSelf : IExponentialFunctions<TSelf>?
     {
         /// <summary>Computes <c>E</c> raised to a given power.</summary>
         /// <param name="x">The power to which <c>E</c> is raised.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPoint.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPoint.cs
index 9b5f975754361..0abcc40ebbbd3 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPoint.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPoint.cs
@@ -9,7 +9,7 @@ public interface IFloatingPoint<TSelf>
         : IFloatingPointConstants<TSelf>,
           INumber<TSelf>,
           ISignedNumber<TSelf>
-        where TSelf : IFloatingPoint<TSelf>
+        where TSelf : IFloatingPoint<TSelf>?
     {
         /// <summary>Computes the ceiling of a value.</summary>
         /// <param name="x">The value whose ceiling is to be computed.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointConstants.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointConstants.cs
index 7bb8bbd229bd1..1ab2d6a4ed55f 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointConstants.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointConstants.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements the interface.</typeparam>
     public interface IFloatingPointConstants<TSelf>
         : INumberBase<TSelf>
-        where TSelf : IFloatingPointConstants<TSelf>
+        where TSelf : IFloatingPointConstants<TSelf>?
     {
         /// <summary>Gets the mathematical constant <c>e</c>.</summary>
         static abstract TSelf E { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointIeee754.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointIeee754.cs
index 7d9e33c994957..35d7b42cd7931 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointIeee754.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IFloatingPointIeee754.cs
@@ -13,7 +13,7 @@ public interface IFloatingPointIeee754<TSelf>
           IPowerFunctions<TSelf>,
           IRootFunctions<TSelf>,
           ITrigonometricFunctions<TSelf>
-        where TSelf : IFloatingPointIeee754<TSelf>
+        where TSelf : IFloatingPointIeee754<TSelf>?
     {
         /// <summary>Gets the smallest value such that can be added to <c>0</c> that does not result in <c>0</c>.</summary>
         static abstract TSelf Epsilon { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IHyperbolicFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IHyperbolicFunctions.cs
index 3fe24e7ef6eba..8929a539145d6 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IHyperbolicFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IHyperbolicFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IHyperbolicFunctions<TSelf>
         : IFloatingPointConstants<TSelf>
-        where TSelf : IHyperbolicFunctions<TSelf>
+        where TSelf : IHyperbolicFunctions<TSelf>?
     {
         /// <summary>Computes the hyperbolic arc-cosine of a value.</summary>
         /// <param name="x">The value, in radians, whose hyperbolic arc-cosine is to be computed.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IIncrementOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IIncrementOperators.cs
index 9024a4a6615ac..9dc434e4c4252 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IIncrementOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IIncrementOperators.cs
@@ -6,7 +6,7 @@ namespace System.Numerics
     /// <summary>Defines a mechanism for incrementing a given value.</summary>
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IIncrementOperators<TSelf>
-        where TSelf : IIncrementOperators<TSelf>
+        where TSelf : IIncrementOperators<TSelf>?
     {
         /// <summary>Increments a value.</summary>
         /// <param name="value">The value to increment.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/ILogarithmicFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/ILogarithmicFunctions.cs
index 668a8b42d1d1f..343327946e423 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/ILogarithmicFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/ILogarithmicFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface ILogarithmicFunctions<TSelf>
         : IFloatingPointConstants<TSelf>
-        where TSelf : ILogarithmicFunctions<TSelf>
+        where TSelf : ILogarithmicFunctions<TSelf>?
     {
         /// <summary>Computes the natural (<c>base-E</c>) logarithm of a value.</summary>
         /// <param name="x">The value whose natural logarithm is to be computed.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMinMaxValue.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMinMaxValue.cs
index fe424d1aa6733..aabfdd10a9fba 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMinMaxValue.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMinMaxValue.cs
@@ -6,7 +6,7 @@ namespace System.Numerics
     /// <summary>Defines a mechanism for getting the minimum and maximum value of a type.</summary>
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IMinMaxValue<TSelf>
-        where TSelf : IMinMaxValue<TSelf>
+        where TSelf : IMinMaxValue<TSelf>?
     {
         /// <summary>Gets the minimum value of the current type.</summary>
         static abstract TSelf MinValue { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IModulusOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IModulusOperators.cs
index fae966ef0be18..772241f9f1686 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IModulusOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IModulusOperators.cs
@@ -9,7 +9,7 @@ namespace System.Numerics
     /// <typeparam name="TResult">The type that contains the modulus or remainder of <typeparamref name="TSelf" /> and <typeparamref name="TOther" />.</typeparam>
     /// <remarks>This type represents the <c>%</c> in C# which is often used to compute the remainder and may differ from an actual modulo operation depending on the type that implements the interface.</remarks>
     public interface IModulusOperators<TSelf, TOther, TResult>
-        where TSelf : IModulusOperators<TSelf, TOther, TResult>
+        where TSelf : IModulusOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Divides two values together to compute their modulus or remainder.</summary>
         /// <param name="left">The value which <paramref name="right" /> divides.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplicativeIdentity.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplicativeIdentity.cs
index fa087d0d8a967..32c7c40db8c91 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplicativeIdentity.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplicativeIdentity.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     /// <typeparam name="TResult">The type that contains the multiplicative identify of <typeparamref name="TSelf" />.</typeparam>
     public interface IMultiplicativeIdentity<TSelf, TResult>
-        where TSelf : IMultiplicativeIdentity<TSelf, TResult>
+        where TSelf : IMultiplicativeIdentity<TSelf, TResult>?
     {
         /// <summary>Gets the multiplicative identity of the current type.</summary>
         static abstract TResult MultiplicativeIdentity { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplyOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplyOperators.cs
index a3e4d52ec42b8..e93e3d466823c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplyOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IMultiplyOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will multiply <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that contains the product of <typeparamref name="TSelf" /> and <typeparamref name="TOther" />.</typeparam>
     public interface IMultiplyOperators<TSelf, TOther, TResult>
-        where TSelf : IMultiplyOperators<TSelf, TOther, TResult>
+        where TSelf : IMultiplyOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Multiplies two values together to compute their product.</summary>
         /// <param name="left">The value which <paramref name="right" /> multiplies.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumber.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumber.cs
index a3413ee78641e..e41d0b999850b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumber.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumber.cs
@@ -14,7 +14,7 @@ public interface INumber<TSelf>
           IComparisonOperators<TSelf, TSelf, bool>,
           IModulusOperators<TSelf, TSelf, TSelf>,
           INumberBase<TSelf>
-        where TSelf : INumber<TSelf>
+        where TSelf : INumber<TSelf>?
     {
         /// <summary>Clamps a value to an inclusive minimum and maximum value.</summary>
         /// <param name="value">The value to clamp.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
index ed159927d5d33..7bc025bf806ce 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/INumberBase.cs
@@ -24,7 +24,7 @@ public interface INumberBase<TSelf>
           ISubtractionOperators<TSelf, TSelf, TSelf>,
           IUnaryPlusOperators<TSelf, TSelf>,
           IUnaryNegationOperators<TSelf, TSelf>
-        where TSelf : INumberBase<TSelf>
+        where TSelf : INumberBase<TSelf>?
     {
         /// <summary>Gets the value <c>1</c> for the type.</summary>
         static abstract TSelf One { get; }
@@ -49,7 +49,9 @@ public interface INumberBase<TSelf>
         /// <exception cref="OverflowException"><paramref name="value" /> is not representable by <typeparamref name="TSelf" />.</exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         static virtual TSelf CreateChecked<TOther>(TOther value)
+#nullable disable
             where TOther : INumberBase<TOther>
+#nullable restore
         {
             TSelf? result;
 
@@ -57,7 +59,7 @@ static virtual TSelf CreateChecked<TOther>(TOther value)
             {
                 result = (TSelf)(object)value;
             }
-            else if (!TSelf.TryConvertFromChecked(value, out result) && !TOther.TryConvertToChecked(value, out result))
+            else if (!TSelf.TryConvertFromChecked(value, out result) && !TOther.TryConvertToChecked<TSelf>(value, out result))
             {
                 ThrowHelper.ThrowNotSupportedException();
             }
@@ -72,7 +74,9 @@ static virtual TSelf CreateChecked<TOther>(TOther value)
         /// <exception cref="NotSupportedException"><typeparamref name="TOther" /> is not supported.</exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         static virtual TSelf CreateSaturating<TOther>(TOther value)
+#nullable disable
             where TOther : INumberBase<TOther>
+#nullable restore
         {
             TSelf? result;
 
@@ -80,7 +84,7 @@ static virtual TSelf CreateSaturating<TOther>(TOther value)
             {
                 result = (TSelf)(object)value;
             }
-            else if (!TSelf.TryConvertFromSaturating(value, out result) && !TOther.TryConvertToSaturating(value, out result))
+            else if (!TSelf.TryConvertFromSaturating(value, out result) && !TOther.TryConvertToSaturating<TSelf>(value, out result))
             {
                 ThrowHelper.ThrowNotSupportedException();
             }
@@ -95,7 +99,9 @@ static virtual TSelf CreateSaturating<TOther>(TOther value)
         /// <exception cref="NotSupportedException"><typeparamref name="TOther" /> is not supported.</exception>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         static virtual TSelf CreateTruncating<TOther>(TOther value)
+#nullable disable
             where TOther : INumberBase<TOther>
+#nullable restore
         {
             TSelf? result;
 
@@ -103,7 +109,7 @@ static virtual TSelf CreateTruncating<TOther>(TOther value)
             {
                 result = (TSelf)(object)value;
             }
-            else if (!TSelf.TryConvertFromTruncating(value, out result) && !TOther.TryConvertToTruncating(value, out result))
+            else if (!TSelf.TryConvertFromTruncating(value, out result) && !TOther.TryConvertToTruncating<TSelf>(value, out result))
             {
                 ThrowHelper.ThrowNotSupportedException();
             }
@@ -268,24 +274,30 @@ static virtual TSelf CreateTruncating<TOther>(TOther value)
         /// <param name="result">On return, contains an instance of <typeparamref name="TSelf" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
         /// <exception cref="OverflowException"><paramref name="value" /> is not representable by <typeparamref name="TSelf" />.</exception>
-        protected static abstract bool TryConvertFromChecked<TOther>(TOther value, [NotNullWhen(true)] out TSelf? result)
+        protected static abstract bool TryConvertFromChecked<TOther>(TOther value, [MaybeNullWhen(false)] out TSelf result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to convert a value to an instance of the current type, saturating any values that fall outside the representable range of the current type.</summary>
         /// <typeparam name="TOther">The type of <paramref name="value" />.</typeparam>
         /// <param name="value">The value which is used to create the instance of <typeparamref name="TSelf" />.</param>
         /// <param name="result">On return, contains an instance of <typeparamref name="TSelf" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
-        protected static abstract bool TryConvertFromSaturating<TOther>(TOther value, [NotNullWhen(true)] out TSelf? result)
+        protected static abstract bool TryConvertFromSaturating<TOther>(TOther value, [MaybeNullWhen(false)] out TSelf result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to convert a value to an instance of the current type, truncating any values that fall outside the representable range of the current type.</summary>
         /// <typeparam name="TOther">The type of <paramref name="value" />.</typeparam>
         /// <param name="value">The value which is used to create the instance of <typeparamref name="TSelf" />.</param>
         /// <param name="result">On return, contains an instance of <typeparamref name="TSelf" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
-        protected static abstract bool TryConvertFromTruncating<TOther>(TOther value, [NotNullWhen(true)] out TSelf? result)
+        protected static abstract bool TryConvertFromTruncating<TOther>(TOther value, [MaybeNullWhen(false)] out TSelf result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to convert an instance of the current type to another type, throwing an overflow exception for any values that fall outside the representable range of the current type.</summary>
         /// <typeparam name="TOther">The type to which <paramref name="value" /> should be converted.</typeparam>
@@ -293,24 +305,30 @@ protected static abstract bool TryConvertFromTruncating<TOther>(TOther value, [N
         /// <param name="result">On return, contains an instance of <typeparamref name="TOther" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
         /// <exception cref="OverflowException"><paramref name="value" /> is not representable by <typeparamref name="TOther" />.</exception>
-        protected static abstract bool TryConvertToChecked<TOther>(TSelf value, [NotNullWhen(true)] out TOther? result)
+        protected static abstract bool TryConvertToChecked<TOther>(TSelf value, [MaybeNullWhen(false)] out TOther result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to convert an instance of the current type to another type, saturating any values that fall outside the representable range of the current type.</summary>
         /// <typeparam name="TOther">The type to which <paramref name="value" /> should be converted.</typeparam>
         /// <param name="value">The value which is used to create the instance of <typeparamref name="TOther" />.</param>
         /// <param name="result">On return, contains an instance of <typeparamref name="TOther" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
-        protected static abstract bool TryConvertToSaturating<TOther>(TSelf value, [NotNullWhen(true)] out TOther? result)
+        protected static abstract bool TryConvertToSaturating<TOther>(TSelf value, [MaybeNullWhen(false)] out TOther result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to convert an instance of the current type to another type, truncating any values that fall outside the representable range of the current type.</summary>
         /// <typeparam name="TOther">The type to which <paramref name="value" /> should be converted.</typeparam>
         /// <param name="value">The value which is used to create the instance of <typeparamref name="TOther" />.</param>
         /// <param name="result">On return, contains an instance of <typeparamref name="TOther" /> converted from <paramref name="value" />.</param>
         /// <returns><c>false</c> if <typeparamref name="TOther" /> is not supported; otherwise, <c>true</c>.</returns>
-        protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [NotNullWhen(true)] out TOther? result)
+        protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [MaybeNullWhen(false)] out TOther result)
+#nullable disable
             where TOther : INumberBase<TOther>;
+#nullable restore
 
         /// <summary>Tries to parses a string into a value.</summary>
         /// <param name="s">The string to parse.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IPowerFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IPowerFunctions.cs
index 9c37729b6a649..5f054364e4c75 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IPowerFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IPowerFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IPowerFunctions<TSelf>
         : INumberBase<TSelf>
-        where TSelf : IPowerFunctions<TSelf>
+        where TSelf : IPowerFunctions<TSelf>?
     {
         /// <summary>Computes a value raised to a given power.</summary>
         /// <param name="x">The value which is raised to the power of <paramref name="x" />.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IRootFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IRootFunctions.cs
index f8eef19b5f6ff..715ab83e5a503 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IRootFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IRootFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface IRootFunctions<TSelf>
         : IFloatingPointConstants<TSelf>
-        where TSelf : IRootFunctions<TSelf>
+        where TSelf : IRootFunctions<TSelf>?
     {
         /// <summary>Computes the cube-root of a value.</summary>
         /// <param name="x">The value whose cube-root is to be computed.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IShiftOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IShiftOperators.cs
index 0ef088e5f5b44..45ccece20b9bd 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IShiftOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IShiftOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type used to specify the amount by which <typeparamref name="TSelf" /> should be shifted.</typeparam>
     /// <typeparam name="TResult">The type that contains the result of shifting <typeparamref name="TSelf" /> by <typeparamref name="TResult" />.</typeparam>
     public interface IShiftOperators<TSelf, TOther, TResult>
-        where TSelf : IShiftOperators<TSelf, TOther, TResult>
+        where TSelf : IShiftOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Shifts a value left by a given amount.</summary>
         /// <param name="value">The value which is shifted left by <paramref name="shiftAmount" />.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/ISignedNumber.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/ISignedNumber.cs
index df1ed28b19563..cc4e9651d5d30 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/ISignedNumber.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/ISignedNumber.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements the interface.</typeparam>
     public interface ISignedNumber<TSelf>
         : INumberBase<TSelf>
-        where TSelf : ISignedNumber<TSelf>
+        where TSelf : ISignedNumber<TSelf>?
     {
         /// <summary>Gets the value <c>-1</c> for the type.</summary>
         static abstract TSelf NegativeOne { get; }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/ISubtractionOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/ISubtractionOperators.cs
index b79879bef3651..e422900d60496 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/ISubtractionOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/ISubtractionOperators.cs
@@ -8,7 +8,7 @@ namespace System.Numerics
     /// <typeparam name="TOther">The type that will be subtracted from <typeparamref name="TSelf" />.</typeparam>
     /// <typeparam name="TResult">The type that contains the difference of <typeparamref name="TOther" /> subtracted from <typeparamref name="TSelf" />.</typeparam>
     public interface ISubtractionOperators<TSelf, TOther, TResult>
-        where TSelf : ISubtractionOperators<TSelf, TOther, TResult>
+        where TSelf : ISubtractionOperators<TSelf, TOther, TResult>?
     {
         /// <summary>Subtracts two values to compute their difference.</summary>
         /// <param name="left">The value from which <paramref name="right" /> is subtracted.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/ITrigonometricFunctions.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/ITrigonometricFunctions.cs
index 8539cd13c5f5e..cac27fad00834 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/ITrigonometricFunctions.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/ITrigonometricFunctions.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     public interface ITrigonometricFunctions<TSelf>
         : IFloatingPointConstants<TSelf>
-        where TSelf : ITrigonometricFunctions<TSelf>
+        where TSelf : ITrigonometricFunctions<TSelf>?
     {
         /// <summary>Computes the arc-cosine of a value.</summary>
         /// <param name="x">The value whose arc-cosine is to be computed.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryNegationOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryNegationOperators.cs
index 6a8ee11fe07a4..0af4580635cb3 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryNegationOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryNegationOperators.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     /// <typeparam name="TResult">The type that contains the result of negating <typeparamref name="TSelf" />.</typeparam>
     public interface IUnaryNegationOperators<TSelf, TResult>
-        where TSelf : IUnaryNegationOperators<TSelf, TResult>
+        where TSelf : IUnaryNegationOperators<TSelf, TResult>?
     {
         /// <summary>Computes the unary negation of a value.</summary>
         /// <param name="value">The value for which to compute its unary negation.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryPlusOperators.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryPlusOperators.cs
index 916c5f13fc5b1..5ba2d43f6a94c 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryPlusOperators.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnaryPlusOperators.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements this interface.</typeparam>
     /// <typeparam name="TResult">The type that contains the result of negating <typeparamref name="TSelf" />.</typeparam>
     public interface IUnaryPlusOperators<TSelf, TResult>
-        where TSelf : IUnaryPlusOperators<TSelf, TResult>
+        where TSelf : IUnaryPlusOperators<TSelf, TResult>?
     {
         /// <summary>Computes the unary plus of a value.</summary>
         /// <param name="value">The value for which to compute its unary plus.</param>
diff --git a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnsignedNumber.cs b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnsignedNumber.cs
index 1cae84b36b7af..d5de09443e2e5 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnsignedNumber.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Numerics/IUnsignedNumber.cs
@@ -7,7 +7,7 @@ namespace System.Numerics
     /// <typeparam name="TSelf">The type that implements the interface.</typeparam>
     public interface IUnsignedNumber<TSelf>
         : INumberBase<TSelf>
-        where TSelf : IUnsignedNumber<TSelf>
+        where TSelf : IUnsignedNumber<TSelf>?
     {
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
index f312049b82fca..9aeef16dadb4d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
@@ -1492,14 +1492,14 @@ private static bool TryConvertFrom<TOther>(TOther value, out NFloat result)
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<NFloat>.TryConvertToChecked<TOther>(NFloat value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<NFloat>.TryConvertToChecked<TOther>(NFloat value, [MaybeNullWhen(false)] out TOther result)
         {
             if (typeof(TOther) == typeof(byte))
             {
@@ -1605,26 +1605,26 @@ static bool INumberBase<NFloat>.TryConvertToChecked<TOther>(NFloat value, [NotNu
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<NFloat>.TryConvertToSaturating<TOther>(NFloat value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<NFloat>.TryConvertToSaturating<TOther>(NFloat value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<NFloat>.TryConvertToTruncating<TOther>(NFloat value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<NFloat>.TryConvertToTruncating<TOther>(NFloat value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
-        private static bool TryConvertTo<TOther>(NFloat value, [NotNullWhen(true)] out TOther result)
+        private static bool TryConvertTo<TOther>(NFloat value, [MaybeNullWhen(false)] out TOther result)
             where TOther : INumberBase<TOther>
         {
             if (typeof(TOther) == typeof(byte))
@@ -1754,7 +1754,7 @@ private static bool TryConvertTo<TOther>(NFloat value, [NotNullWhen(true)] out T
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/SByte.cs b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
index 8b9dc686c15a2..afd9b04f08e26 100644
--- a/src/libraries/System.Private.CoreLib/src/System/SByte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
@@ -1114,7 +1114,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out sbyte res
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<sbyte>.TryConvertToChecked<TOther>(sbyte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<sbyte>.TryConvertToChecked<TOther>(sbyte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1175,14 +1175,14 @@ static bool INumberBase<sbyte>.TryConvertToChecked<TOther>(sbyte value, [NotNull
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<sbyte>.TryConvertToSaturating<TOther>(sbyte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<sbyte>.TryConvertToSaturating<TOther>(sbyte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1243,14 +1243,14 @@ static bool INumberBase<sbyte>.TryConvertToSaturating<TOther>(sbyte value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<sbyte>.TryConvertToTruncating<TOther>(sbyte value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<sbyte>.TryConvertToTruncating<TOther>(sbyte value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1311,7 +1311,7 @@ static bool INumberBase<sbyte>.TryConvertToTruncating<TOther>(sbyte value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Single.cs b/src/libraries/System.Private.CoreLib/src/System/Single.cs
index cd31393df23ae..54e1ef148e9f1 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Single.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Single.cs
@@ -1223,7 +1223,7 @@ private static bool TryConvertFrom<TOther>(TOther value, out float result)
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<float>.TryConvertToChecked<TOther>(float value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<float>.TryConvertToChecked<TOther>(float value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1284,26 +1284,26 @@ static bool INumberBase<float>.TryConvertToChecked<TOther>(float value, [NotNull
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<float>.TryConvertToSaturating<TOther>(float value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<float>.TryConvertToSaturating<TOther>(float value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<float>.TryConvertToTruncating<TOther>(float value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<float>.TryConvertToTruncating<TOther>(float value, [MaybeNullWhen(false)] out TOther result)
         {
             return TryConvertTo<TOther>(value, out result);
         }
 
-        private static bool TryConvertTo<TOther>(float value, [NotNullWhen(true)] out TOther result)
+        private static bool TryConvertTo<TOther>(float value, [MaybeNullWhen(false)] out TOther result)
             where TOther : INumberBase<TOther>
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
@@ -1382,7 +1382,7 @@ private static bool TryConvertTo<TOther>(float value, [NotNullWhen(true)] out TO
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt128.cs b/src/libraries/System.Private.CoreLib/src/System/UInt128.cs
index e75cb7f0650af..fb30f2c9996a2 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt128.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt128.cs
@@ -1793,7 +1793,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out UInt128 r
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<UInt128>.TryConvertToChecked<TOther>(UInt128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<UInt128>.TryConvertToChecked<TOther>(UInt128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1860,14 +1860,14 @@ static bool INumberBase<UInt128>.TryConvertToChecked<TOther>(UInt128 value, [Not
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<UInt128>.TryConvertToSaturating<TOther>(UInt128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<UInt128>.TryConvertToSaturating<TOther>(UInt128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1940,14 +1940,14 @@ static bool INumberBase<UInt128>.TryConvertToSaturating<TOther>(UInt128 value, [
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<UInt128>.TryConvertToTruncating<TOther>(UInt128 value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<UInt128>.TryConvertToTruncating<TOther>(UInt128 value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -2014,7 +2014,7 @@ static bool INumberBase<UInt128>.TryConvertToTruncating<TOther>(UInt128 value, [
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
index 19069064d1369..5e50f54f64193 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
@@ -946,7 +946,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out ushort re
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ushort>.TryConvertToChecked<TOther>(ushort value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ushort>.TryConvertToChecked<TOther>(ushort value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1013,14 +1013,14 @@ static bool INumberBase<ushort>.TryConvertToChecked<TOther>(ushort value, [NotNu
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ushort>.TryConvertToSaturating<TOther>(ushort value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ushort>.TryConvertToSaturating<TOther>(ushort value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1087,14 +1087,14 @@ static bool INumberBase<ushort>.TryConvertToSaturating<TOther>(ushort value, [No
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ushort>.TryConvertToTruncating<TOther>(ushort value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ushort>.TryConvertToTruncating<TOther>(ushort value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1161,7 +1161,7 @@ static bool INumberBase<ushort>.TryConvertToTruncating<TOther>(ushort value, [No
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
index cce0a8b78a629..4f137f25dd303 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
@@ -949,7 +949,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out uint resu
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<uint>.TryConvertToChecked<TOther>(uint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<uint>.TryConvertToChecked<TOther>(uint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1016,14 +1016,14 @@ static bool INumberBase<uint>.TryConvertToChecked<TOther>(uint value, [NotNullWh
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<uint>.TryConvertToSaturating<TOther>(uint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<uint>.TryConvertToSaturating<TOther>(uint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1096,14 +1096,14 @@ static bool INumberBase<uint>.TryConvertToSaturating<TOther>(uint value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<uint>.TryConvertToTruncating<TOther>(uint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<uint>.TryConvertToTruncating<TOther>(uint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1170,7 +1170,7 @@ static bool INumberBase<uint>.TryConvertToTruncating<TOther>(uint value, [NotNul
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
index f3010971b12a2..c3f210e350dad 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
@@ -948,7 +948,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out ulong res
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ulong>.TryConvertToChecked<TOther>(ulong value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ulong>.TryConvertToChecked<TOther>(ulong value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1015,14 +1015,14 @@ static bool INumberBase<ulong>.TryConvertToChecked<TOther>(ulong value, [NotNull
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ulong>.TryConvertToSaturating<TOther>(ulong value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ulong>.TryConvertToSaturating<TOther>(ulong value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1089,14 +1089,14 @@ static bool INumberBase<ulong>.TryConvertToSaturating<TOther>(ulong value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<ulong>.TryConvertToTruncating<TOther>(ulong value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<ulong>.TryConvertToTruncating<TOther>(ulong value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1163,7 +1163,7 @@ static bool INumberBase<ulong>.TryConvertToTruncating<TOther>(ulong value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs b/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
index 29403c4e09907..04c8384c34957 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UIntPtr.cs
@@ -933,7 +933,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out nuint res
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nuint>.TryConvertToChecked<TOther>(nuint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nuint>.TryConvertToChecked<TOther>(nuint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1000,14 +1000,14 @@ static bool INumberBase<nuint>.TryConvertToChecked<TOther>(nuint value, [NotNull
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nuint>.TryConvertToSaturating<TOther>(nuint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nuint>.TryConvertToSaturating<TOther>(nuint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1074,14 +1074,14 @@ static bool INumberBase<nuint>.TryConvertToSaturating<TOther>(nuint value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<nuint>.TryConvertToTruncating<TOther>(nuint value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<nuint>.TryConvertToTruncating<TOther>(nuint value, [MaybeNullWhen(false)] out TOther result)
         {
             // In order to reduce overall code duplication and improve the inlinabilty of these
             // methods for the corelib types we have `ConvertFrom` handle the same sign and
@@ -1148,7 +1148,7 @@ static bool INumberBase<nuint>.TryConvertToTruncating<TOther>(nuint value, [NotN
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.cs b/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.cs
index b5a7b209486d9..c1ace3807df84 100644
--- a/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.cs
+++ b/src/libraries/System.Runtime.InteropServices/ref/System.Runtime.InteropServices.cs
@@ -1314,9 +1314,9 @@ public static void Free(void* ptr) { }
         static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertFromChecked<TOther>(TOther value, out System.Runtime.InteropServices.NFloat result) { throw null; }
         static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertFromSaturating<TOther>(TOther value, out System.Runtime.InteropServices.NFloat result) { throw null; }
         static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertFromTruncating<TOther>(TOther value, out System.Runtime.InteropServices.NFloat result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToChecked<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToSaturating<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToTruncating<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToChecked<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToSaturating<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Runtime.InteropServices.NFloat>.TryConvertToTruncating<TOther>(System.Runtime.InteropServices.NFloat value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static System.Runtime.InteropServices.NFloat System.Numerics.ISubtractionOperators<System.Runtime.InteropServices.NFloat, System.Runtime.InteropServices.NFloat, System.Runtime.InteropServices.NFloat>.operator checked -(System.Runtime.InteropServices.NFloat left, System.Runtime.InteropServices.NFloat right) { throw null; }
         static System.Runtime.InteropServices.NFloat System.Numerics.IUnaryNegationOperators<System.Runtime.InteropServices.NFloat, System.Runtime.InteropServices.NFloat>.operator checked -(System.Runtime.InteropServices.NFloat value) { throw null; }
         public static System.Runtime.InteropServices.NFloat Tan(System.Runtime.InteropServices.NFloat x) { throw null; }
diff --git a/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.cs b/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.cs
index 443aae6338ffc..0d371c4d7886c 100644
--- a/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.cs
+++ b/src/libraries/System.Runtime.Numerics/ref/System.Runtime.Numerics.cs
@@ -218,9 +218,9 @@ namespace System.Numerics
         static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertFromChecked<TOther>(TOther value, out System.Numerics.BigInteger result) { throw null; }
         static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertFromSaturating<TOther>(TOther value, out System.Numerics.BigInteger result) { throw null; }
         static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertFromTruncating<TOther>(TOther value, out System.Numerics.BigInteger result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToChecked<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToSaturating<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToTruncating<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToChecked<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToSaturating<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.BigInteger>.TryConvertToTruncating<TOther>(System.Numerics.BigInteger value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static System.Numerics.BigInteger System.Numerics.INumber<System.Numerics.BigInteger>.MaxNumber(System.Numerics.BigInteger x, System.Numerics.BigInteger y) { throw null; }
         static System.Numerics.BigInteger System.Numerics.INumber<System.Numerics.BigInteger>.MinNumber(System.Numerics.BigInteger x, System.Numerics.BigInteger y) { throw null; }
         static int System.Numerics.INumber<System.Numerics.BigInteger>.Sign(System.Numerics.BigInteger value) { throw null; }
@@ -367,9 +367,9 @@ namespace System.Numerics
         static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertFromChecked<TOther>(TOther value, out System.Numerics.Complex result) { throw null; }
         static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertFromSaturating<TOther>(TOther value, out System.Numerics.Complex result) { throw null; }
         static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertFromTruncating<TOther>(TOther value, out System.Numerics.Complex result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToChecked<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToSaturating<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToTruncating<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToChecked<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToSaturating<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Numerics.Complex>.TryConvertToTruncating<TOther>(System.Numerics.Complex value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         public static System.Numerics.Complex Tan(System.Numerics.Complex value) { throw null; }
         public static System.Numerics.Complex Tanh(System.Numerics.Complex value) { throw null; }
         public override string ToString() { throw null; }
diff --git a/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs b/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
index 4956fac177a40..1175591a97e00 100644
--- a/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
+++ b/src/libraries/System.Runtime.Numerics/src/System/Numerics/BigInteger.cs
@@ -4489,7 +4489,7 @@ private static bool TryConvertFromTruncating<TOther>(TOther value, out BigIntege
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<BigInteger>.TryConvertToChecked<TOther>(BigInteger value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<BigInteger>.TryConvertToChecked<TOther>(BigInteger value, [MaybeNullWhen(false)] out TOther result)
         {
             if (typeof(TOther) == typeof(byte))
             {
@@ -4601,14 +4601,14 @@ static bool INumberBase<BigInteger>.TryConvertToChecked<TOther>(BigInteger value
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<BigInteger>.TryConvertToSaturating<TOther>(BigInteger value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<BigInteger>.TryConvertToSaturating<TOther>(BigInteger value, [MaybeNullWhen(false)] out TOther result)
         {
             if (typeof(TOther) == typeof(byte))
             {
@@ -4794,14 +4794,14 @@ static bool INumberBase<BigInteger>.TryConvertToSaturating<TOther>(BigInteger va
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<BigInteger>.TryConvertToTruncating<TOther>(BigInteger value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<BigInteger>.TryConvertToTruncating<TOther>(BigInteger value, [MaybeNullWhen(false)] out TOther result)
         {
             if (typeof(TOther) == typeof(byte))
             {
@@ -5190,7 +5190,7 @@ static bool INumberBase<BigInteger>.TryConvertToTruncating<TOther>(BigInteger va
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs b/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs
index 97c0a5558f5e1..f2e2220b6ba08 100644
--- a/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs
+++ b/src/libraries/System.Runtime.Numerics/src/System/Numerics/Complex.cs
@@ -1613,7 +1613,7 @@ private static bool TryConvertFrom<TOther>(TOther value, out Complex result)
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToChecked{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Complex>.TryConvertToChecked<TOther>(Complex value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Complex>.TryConvertToChecked<TOther>(Complex value, [MaybeNullWhen(false)] out TOther result)
         {
             // Complex numbers with an imaginary part can't be represented as a "real number"
             // so we'll throw an OverflowException for this scenario for integer types and
@@ -1805,14 +1805,14 @@ static bool INumberBase<Complex>.TryConvertToChecked<TOther>(Complex value, [Not
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToSaturating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Complex>.TryConvertToSaturating<TOther>(Complex value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Complex>.TryConvertToSaturating<TOther>(Complex value, [MaybeNullWhen(false)] out TOther result)
         {
             // Complex numbers with an imaginary part can't be represented as a "real number"
             // and there isn't really a well-defined way to "saturate" to just a real value.
@@ -1949,14 +1949,14 @@ static bool INumberBase<Complex>.TryConvertToSaturating<TOther>(Complex value, [
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
 
         /// <inheritdoc cref="INumberBase{TSelf}.TryConvertToTruncating{TOther}(TSelf, out TOther)" />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        static bool INumberBase<Complex>.TryConvertToTruncating<TOther>(Complex value, [NotNullWhen(true)] out TOther result)
+        static bool INumberBase<Complex>.TryConvertToTruncating<TOther>(Complex value, [MaybeNullWhen(false)] out TOther result)
         {
             // Complex numbers with an imaginary part can't be represented as a "real number"
             // so we'll only consider the real part for the purposes of truncation.
@@ -2085,7 +2085,7 @@ static bool INumberBase<Complex>.TryConvertToTruncating<TOther>(Complex value, [
             }
             else
             {
-                result = default!;
+                result = default;
                 return false;
             }
         }
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.cs b/src/libraries/System.Runtime/ref/System.Runtime.cs
index 5d04d15a81dc9..6ad2debb08822 100644
--- a/src/libraries/System.Runtime/ref/System.Runtime.cs
+++ b/src/libraries/System.Runtime/ref/System.Runtime.cs
@@ -818,9 +818,9 @@ public static void SetByte(System.Array array, int index, byte value) { }
         static bool System.Numerics.INumberBase<byte>.TryConvertFromChecked<TOther>(TOther value, out byte result) { throw null; }
         static bool System.Numerics.INumberBase<byte>.TryConvertFromSaturating<TOther>(TOther value, out byte result) { throw null; }
         static bool System.Numerics.INumberBase<byte>.TryConvertFromTruncating<TOther>(TOther value, out byte result) { throw null; }
-        static bool System.Numerics.INumberBase<byte>.TryConvertToChecked<TOther>(byte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<byte>.TryConvertToSaturating<TOther>(byte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<byte>.TryConvertToTruncating<TOther>(byte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<byte>.TryConvertToChecked<TOther>(byte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<byte>.TryConvertToSaturating<TOther>(byte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<byte>.TryConvertToTruncating<TOther>(byte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static byte System.Numerics.INumber<byte>.CopySign(byte value, byte sign) { throw null; }
         static byte System.Numerics.INumber<byte>.MaxNumber(byte x, byte y) { throw null; }
         static byte System.Numerics.INumber<byte>.MinNumber(byte x, byte y) { throw null; }
@@ -1000,9 +1000,9 @@ public CannotUnloadAppDomainException(string? message, System.Exception? innerEx
         static bool System.Numerics.INumberBase<char>.TryConvertFromChecked<TOther>(TOther value, out char result) { throw null; }
         static bool System.Numerics.INumberBase<char>.TryConvertFromSaturating<TOther>(TOther value, out char result) { throw null; }
         static bool System.Numerics.INumberBase<char>.TryConvertFromTruncating<TOther>(TOther value, out char result) { throw null; }
-        static bool System.Numerics.INumberBase<char>.TryConvertToChecked<TOther>(char value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<char>.TryConvertToSaturating<TOther>(char value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<char>.TryConvertToTruncating<TOther>(char value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<char>.TryConvertToChecked<TOther>(char value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<char>.TryConvertToSaturating<TOther>(char value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<char>.TryConvertToTruncating<TOther>(char value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static bool System.Numerics.INumberBase<char>.TryParse(System.ReadOnlySpan<char> s, System.Globalization.NumberStyles style, System.IFormatProvider? provider, out char result) { throw null; }
         static bool System.Numerics.INumberBase<char>.TryParse([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] string? s, System.Globalization.NumberStyles style, System.IFormatProvider? provider, out char result) { throw null; }
         static char System.Numerics.IShiftOperators<char, int, char>.operator <<(char value, int shiftAmount) { throw null; }
@@ -2016,9 +2016,9 @@ public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, S
         static bool System.Numerics.INumberBase<decimal>.TryConvertFromChecked<TOther>(TOther value, out decimal result) { throw null; }
         static bool System.Numerics.INumberBase<decimal>.TryConvertFromSaturating<TOther>(TOther value, out decimal result) { throw null; }
         static bool System.Numerics.INumberBase<decimal>.TryConvertFromTruncating<TOther>(TOther value, out decimal result) { throw null; }
-        static bool System.Numerics.INumberBase<decimal>.TryConvertToChecked<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<decimal>.TryConvertToSaturating<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<decimal>.TryConvertToTruncating<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<decimal>.TryConvertToChecked<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<decimal>.TryConvertToSaturating<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<decimal>.TryConvertToTruncating<TOther>(decimal value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static decimal System.Numerics.INumber<decimal>.MaxNumber(decimal x, decimal y) { throw null; }
         static decimal System.Numerics.INumber<decimal>.MinNumber(decimal x, decimal y) { throw null; }
         void System.Runtime.Serialization.IDeserializationCallback.OnDeserialization(object? sender) { }
@@ -2266,9 +2266,9 @@ public DivideByZeroException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<double>.TryConvertFromChecked<TOther>(TOther value, out double result) { throw null; }
         static bool System.Numerics.INumberBase<double>.TryConvertFromSaturating<TOther>(TOther value, out double result) { throw null; }
         static bool System.Numerics.INumberBase<double>.TryConvertFromTruncating<TOther>(TOther value, out double result) { throw null; }
-        static bool System.Numerics.INumberBase<double>.TryConvertToChecked<TOther>(double value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<double>.TryConvertToSaturating<TOther>(double value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<double>.TryConvertToTruncating<TOther>(double value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<double>.TryConvertToChecked<TOther>(double value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<double>.TryConvertToSaturating<TOther>(double value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<double>.TryConvertToTruncating<TOther>(double value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static double System.Numerics.ISubtractionOperators<double, double, double>.operator -(double left, double right) { throw null; }
         static double System.Numerics.IUnaryNegationOperators<double, double>.operator -(double value) { throw null; }
         static double System.Numerics.IUnaryPlusOperators<double, double>.operator +(double value) { throw null; }
@@ -2908,9 +2908,9 @@ public enum GCNotificationStatus
         static bool System.Numerics.INumberBase<System.Half>.TryConvertFromChecked<TOther>(TOther value, out System.Half result) { throw null; }
         static bool System.Numerics.INumberBase<System.Half>.TryConvertFromSaturating<TOther>(TOther value, out System.Half result) { throw null; }
         static bool System.Numerics.INumberBase<System.Half>.TryConvertFromTruncating<TOther>(TOther value, out System.Half result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Half>.TryConvertToChecked<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Half>.TryConvertToSaturating<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Half>.TryConvertToTruncating<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Half>.TryConvertToChecked<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Half>.TryConvertToSaturating<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Half>.TryConvertToTruncating<TOther>(System.Half value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         public static System.Half Tan(System.Half x) { throw null; }
         public static System.Half Tanh(System.Half x) { throw null; }
         public static System.Half TanPi(System.Half x) { throw null; }
@@ -3209,9 +3209,9 @@ public InsufficientMemoryException(string? message, System.Exception? innerExcep
         static bool System.Numerics.INumberBase<System.Int128>.TryConvertFromChecked<TOther>(TOther value, out System.Int128 result) { throw null; }
         static bool System.Numerics.INumberBase<System.Int128>.TryConvertFromSaturating<TOther>(TOther value, out System.Int128 result) { throw null; }
         static bool System.Numerics.INumberBase<System.Int128>.TryConvertFromTruncating<TOther>(TOther value, out System.Int128 result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToChecked<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToSaturating<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToTruncating<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToChecked<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToSaturating<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.Int128>.TryConvertToTruncating<TOther>(System.Int128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static System.Int128 System.Numerics.INumber<System.Int128>.MaxNumber(System.Int128 x, System.Int128 y) { throw null; }
         static System.Int128 System.Numerics.INumber<System.Int128>.MinNumber(System.Int128 x, System.Int128 y) { throw null; }
         public override string ToString() { throw null; }
@@ -3334,9 +3334,9 @@ public InsufficientMemoryException(string? message, System.Exception? innerExcep
         static bool System.Numerics.INumberBase<short>.TryConvertFromChecked<TOther>(TOther value, out short result) { throw null; }
         static bool System.Numerics.INumberBase<short>.TryConvertFromSaturating<TOther>(TOther value, out short result) { throw null; }
         static bool System.Numerics.INumberBase<short>.TryConvertFromTruncating<TOther>(TOther value, out short result) { throw null; }
-        static bool System.Numerics.INumberBase<short>.TryConvertToChecked<TOther>(short value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<short>.TryConvertToSaturating<TOther>(short value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<short>.TryConvertToTruncating<TOther>(short value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<short>.TryConvertToChecked<TOther>(short value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<short>.TryConvertToSaturating<TOther>(short value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<short>.TryConvertToTruncating<TOther>(short value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static short System.Numerics.INumber<short>.MaxNumber(short x, short y) { throw null; }
         static short System.Numerics.INumber<short>.MinNumber(short x, short y) { throw null; }
         static short System.Numerics.IShiftOperators<short, int, short>.operator <<(short value, int shiftAmount) { throw null; }
@@ -3467,9 +3467,9 @@ public InsufficientMemoryException(string? message, System.Exception? innerExcep
         static bool System.Numerics.INumberBase<int>.TryConvertFromChecked<TOther>(TOther value, out int result) { throw null; }
         static bool System.Numerics.INumberBase<int>.TryConvertFromSaturating<TOther>(TOther value, out int result) { throw null; }
         static bool System.Numerics.INumberBase<int>.TryConvertFromTruncating<TOther>(TOther value, out int result) { throw null; }
-        static bool System.Numerics.INumberBase<int>.TryConvertToChecked<TOther>(int value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<int>.TryConvertToSaturating<TOther>(int value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<int>.TryConvertToTruncating<TOther>(int value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<int>.TryConvertToChecked<TOther>(int value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<int>.TryConvertToSaturating<TOther>(int value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<int>.TryConvertToTruncating<TOther>(int value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static int System.Numerics.INumber<int>.MaxNumber(int x, int y) { throw null; }
         static int System.Numerics.INumber<int>.MinNumber(int x, int y) { throw null; }
         static int System.Numerics.IShiftOperators<int, int, int>.operator <<(int value, int shiftAmount) { throw null; }
@@ -3600,9 +3600,9 @@ public InsufficientMemoryException(string? message, System.Exception? innerExcep
         static bool System.Numerics.INumberBase<long>.TryConvertFromChecked<TOther>(TOther value, out long result) { throw null; }
         static bool System.Numerics.INumberBase<long>.TryConvertFromSaturating<TOther>(TOther value, out long result) { throw null; }
         static bool System.Numerics.INumberBase<long>.TryConvertFromTruncating<TOther>(TOther value, out long result) { throw null; }
-        static bool System.Numerics.INumberBase<long>.TryConvertToChecked<TOther>(long value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<long>.TryConvertToSaturating<TOther>(long value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<long>.TryConvertToTruncating<TOther>(long value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<long>.TryConvertToChecked<TOther>(long value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<long>.TryConvertToSaturating<TOther>(long value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<long>.TryConvertToTruncating<TOther>(long value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static long System.Numerics.INumber<long>.MaxNumber(long x, long y) { throw null; }
         static long System.Numerics.INumber<long>.MinNumber(long x, long y) { throw null; }
         static long System.Numerics.IShiftOperators<long, int, long>.operator <<(long value, int shiftAmount) { throw null; }
@@ -3735,9 +3735,9 @@ public InsufficientMemoryException(string? message, System.Exception? innerExcep
         static bool System.Numerics.INumberBase<nint>.TryConvertFromChecked<TOther>(TOther value, out nint result) { throw null; }
         static bool System.Numerics.INumberBase<nint>.TryConvertFromSaturating<TOther>(TOther value, out nint result) { throw null; }
         static bool System.Numerics.INumberBase<nint>.TryConvertFromTruncating<TOther>(TOther value, out nint result) { throw null; }
-        static bool System.Numerics.INumberBase<nint>.TryConvertToChecked<TOther>(nint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<nint>.TryConvertToSaturating<TOther>(nint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<nint>.TryConvertToTruncating<TOther>(nint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nint>.TryConvertToChecked<TOther>(nint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nint>.TryConvertToSaturating<TOther>(nint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nint>.TryConvertToTruncating<TOther>(nint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static nint System.Numerics.INumber<nint>.MaxNumber(nint x, nint y) { throw null; }
         static nint System.Numerics.INumber<nint>.MinNumber(nint x, nint y) { throw null; }
         static nint System.Numerics.IShiftOperators<nint, int, nint>.operator <<(nint value, int shiftAmount) { throw null; }
@@ -3804,7 +3804,7 @@ public partial interface IObserver<in T>
         void OnError(System.Exception error);
         void OnNext(T value);
     }
-    public partial interface IParsable<TSelf> where TSelf : System.IParsable<TSelf>
+    public partial interface IParsable<TSelf> where TSelf : System.IParsable<TSelf>?
     {
         static abstract TSelf Parse(string s, System.IFormatProvider? provider);
         static abstract bool TryParse([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] string? s, System.IFormatProvider? provider, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TSelf result);
@@ -3817,7 +3817,7 @@ public partial interface ISpanFormattable : System.IFormattable
     {
         bool TryFormat(System.Span<char> destination, out int charsWritten, System.ReadOnlySpan<char> format, System.IFormatProvider? provider);
     }
-    public partial interface ISpanParsable<TSelf> : System.IParsable<TSelf> where TSelf : System.ISpanParsable<TSelf>
+    public partial interface ISpanParsable<TSelf> : System.IParsable<TSelf> where TSelf : System.ISpanParsable<TSelf>?
     {
         static abstract TSelf Parse(System.ReadOnlySpan<char> s, System.IFormatProvider? provider);
         static abstract bool TryParse(System.ReadOnlySpan<char> s, System.IFormatProvider? provider, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TSelf result);
@@ -4664,9 +4664,9 @@ public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, S
         static bool System.Numerics.INumberBase<sbyte>.TryConvertFromChecked<TOther>(TOther value, out sbyte result) { throw null; }
         static bool System.Numerics.INumberBase<sbyte>.TryConvertFromSaturating<TOther>(TOther value, out sbyte result) { throw null; }
         static bool System.Numerics.INumberBase<sbyte>.TryConvertFromTruncating<TOther>(TOther value, out sbyte result) { throw null; }
-        static bool System.Numerics.INumberBase<sbyte>.TryConvertToChecked<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<sbyte>.TryConvertToSaturating<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<sbyte>.TryConvertToTruncating<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<sbyte>.TryConvertToChecked<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<sbyte>.TryConvertToSaturating<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<sbyte>.TryConvertToTruncating<TOther>(sbyte value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static sbyte System.Numerics.INumber<sbyte>.MaxNumber(sbyte x, sbyte y) { throw null; }
         static sbyte System.Numerics.INumber<sbyte>.MinNumber(sbyte x, sbyte y) { throw null; }
         static sbyte System.Numerics.IShiftOperators<sbyte, int, sbyte>.operator <<(sbyte value, int shiftAmount) { throw null; }
@@ -4863,9 +4863,9 @@ public SerializableAttribute() { }
         static bool System.Numerics.INumberBase<float>.TryConvertFromChecked<TOther>(TOther value, out float result) { throw null; }
         static bool System.Numerics.INumberBase<float>.TryConvertFromSaturating<TOther>(TOther value, out float result) { throw null; }
         static bool System.Numerics.INumberBase<float>.TryConvertFromTruncating<TOther>(TOther value, out float result) { throw null; }
-        static bool System.Numerics.INumberBase<float>.TryConvertToChecked<TOther>(float value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<float>.TryConvertToSaturating<TOther>(float value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<float>.TryConvertToTruncating<TOther>(float value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<float>.TryConvertToChecked<TOther>(float value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<float>.TryConvertToSaturating<TOther>(float value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<float>.TryConvertToTruncating<TOther>(float value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static float System.Numerics.ISubtractionOperators<float, float, float>.operator -(float left, float right) { throw null; }
         static float System.Numerics.IUnaryNegationOperators<float, float>.operator -(float value) { throw null; }
         static float System.Numerics.IUnaryPlusOperators<float, float>.operator +(float value) { throw null; }
@@ -6221,9 +6221,9 @@ public TypeUnloadedException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<System.UInt128>.TryConvertFromChecked<TOther>(TOther value, out System.UInt128 result) { throw null; }
         static bool System.Numerics.INumberBase<System.UInt128>.TryConvertFromSaturating<TOther>(TOther value, out System.UInt128 result) { throw null; }
         static bool System.Numerics.INumberBase<System.UInt128>.TryConvertFromTruncating<TOther>(TOther value, out System.UInt128 result) { throw null; }
-        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToChecked<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToSaturating<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToTruncating<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToChecked<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToSaturating<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<System.UInt128>.TryConvertToTruncating<TOther>(System.UInt128 value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static System.UInt128 System.Numerics.INumber<System.UInt128>.CopySign(System.UInt128 value, System.UInt128 sign) { throw null; }
         static System.UInt128 System.Numerics.INumber<System.UInt128>.MaxNumber(System.UInt128 x, System.UInt128 y) { throw null; }
         static System.UInt128 System.Numerics.INumber<System.UInt128>.MinNumber(System.UInt128 x, System.UInt128 y) { throw null; }
@@ -6346,9 +6346,9 @@ public TypeUnloadedException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<ushort>.TryConvertFromChecked<TOther>(TOther value, out ushort result) { throw null; }
         static bool System.Numerics.INumberBase<ushort>.TryConvertFromSaturating<TOther>(TOther value, out ushort result) { throw null; }
         static bool System.Numerics.INumberBase<ushort>.TryConvertFromTruncating<TOther>(TOther value, out ushort result) { throw null; }
-        static bool System.Numerics.INumberBase<ushort>.TryConvertToChecked<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<ushort>.TryConvertToSaturating<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<ushort>.TryConvertToTruncating<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ushort>.TryConvertToChecked<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ushort>.TryConvertToSaturating<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ushort>.TryConvertToTruncating<TOther>(ushort value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static ushort System.Numerics.INumber<ushort>.CopySign(ushort value, ushort sign) { throw null; }
         static ushort System.Numerics.INumber<ushort>.MaxNumber(ushort x, ushort y) { throw null; }
         static ushort System.Numerics.INumber<ushort>.MinNumber(ushort x, ushort y) { throw null; }
@@ -6479,9 +6479,9 @@ public TypeUnloadedException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<uint>.TryConvertFromChecked<TOther>(TOther value, out uint result) { throw null; }
         static bool System.Numerics.INumberBase<uint>.TryConvertFromSaturating<TOther>(TOther value, out uint result) { throw null; }
         static bool System.Numerics.INumberBase<uint>.TryConvertFromTruncating<TOther>(TOther value, out uint result) { throw null; }
-        static bool System.Numerics.INumberBase<uint>.TryConvertToChecked<TOther>(uint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<uint>.TryConvertToSaturating<TOther>(uint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<uint>.TryConvertToTruncating<TOther>(uint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<uint>.TryConvertToChecked<TOther>(uint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<uint>.TryConvertToSaturating<TOther>(uint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<uint>.TryConvertToTruncating<TOther>(uint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static uint System.Numerics.INumber<uint>.CopySign(uint value, uint sign) { throw null; }
         static uint System.Numerics.INumber<uint>.MaxNumber(uint x, uint y) { throw null; }
         static uint System.Numerics.INumber<uint>.MinNumber(uint x, uint y) { throw null; }
@@ -6612,9 +6612,9 @@ public TypeUnloadedException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<ulong>.TryConvertFromChecked<TOther>(TOther value, out ulong result) { throw null; }
         static bool System.Numerics.INumberBase<ulong>.TryConvertFromSaturating<TOther>(TOther value, out ulong result) { throw null; }
         static bool System.Numerics.INumberBase<ulong>.TryConvertFromTruncating<TOther>(TOther value, out ulong result) { throw null; }
-        static bool System.Numerics.INumberBase<ulong>.TryConvertToChecked<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<ulong>.TryConvertToSaturating<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<ulong>.TryConvertToTruncating<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ulong>.TryConvertToChecked<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ulong>.TryConvertToSaturating<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<ulong>.TryConvertToTruncating<TOther>(ulong value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static ulong System.Numerics.INumber<ulong>.CopySign(ulong value, ulong sign) { throw null; }
         static ulong System.Numerics.INumber<ulong>.MaxNumber(ulong x, ulong y) { throw null; }
         static ulong System.Numerics.INumber<ulong>.MinNumber(ulong x, ulong y) { throw null; }
@@ -6744,9 +6744,9 @@ public TypeUnloadedException(string? message, System.Exception? innerException)
         static bool System.Numerics.INumberBase<nuint>.TryConvertFromChecked<TOther>(TOther value, out nuint result) { throw null; }
         static bool System.Numerics.INumberBase<nuint>.TryConvertFromSaturating<TOther>(TOther value, out nuint result) { throw null; }
         static bool System.Numerics.INumberBase<nuint>.TryConvertFromTruncating<TOther>(TOther value, out nuint result) { throw null; }
-        static bool System.Numerics.INumberBase<nuint>.TryConvertToChecked<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<nuint>.TryConvertToSaturating<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
-        static bool System.Numerics.INumberBase<nuint>.TryConvertToTruncating<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nuint>.TryConvertToChecked<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nuint>.TryConvertToSaturating<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
+        static bool System.Numerics.INumberBase<nuint>.TryConvertToTruncating<TOther>(nuint value, [System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute(false)] out TOther result) { throw null; }
         static nuint System.Numerics.INumber<nuint>.CopySign(nuint value, nuint sign) { throw null; }
         static nuint System.Numerics.INumber<nuint>.MaxNumber(nuint x, nuint y) { throw null; }
         static nuint System.Numerics.INumber<nuint>.MinNumber(nuint x, nuint y) { throw null; }
@@ -10218,19 +10218,19 @@ public static partial class BitOperations
         [System.CLSCompliantAttribute(false)]
         public static int TrailingZeroCount(nuint value) { throw null; }
     }
-    public partial interface IAdditionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IAdditionOperators<TSelf, TOther, TResult>
+    public partial interface IAdditionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IAdditionOperators<TSelf, TOther, TResult>?
     {
         static abstract TResult operator +(TSelf left, TOther right);
         static virtual TResult operator checked +(TSelf left, TOther right) { throw null; }
     }
-    public partial interface IAdditiveIdentity<TSelf, TResult> where TSelf : System.Numerics.IAdditiveIdentity<TSelf, TResult>
+    public partial interface IAdditiveIdentity<TSelf, TResult> where TSelf : System.Numerics.IAdditiveIdentity<TSelf, TResult>?
     {
         static abstract TResult AdditiveIdentity { get; }
     }
-    public partial interface IBinaryFloatingPointIeee754<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBinaryNumber<TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IExponentialFunctions<TSelf>, System.Numerics.IFloatingPoint<TSelf>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IFloatingPointIeee754<TSelf>, System.Numerics.IHyperbolicFunctions<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.ILogarithmicFunctions<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IPowerFunctions<TSelf>, System.Numerics.IRootFunctions<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.ITrigonometricFunctions<TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryFloatingPointIeee754<TSelf>
+    public partial interface IBinaryFloatingPointIeee754<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBinaryNumber<TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IExponentialFunctions<TSelf>, System.Numerics.IFloatingPoint<TSelf>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IFloatingPointIeee754<TSelf>, System.Numerics.IHyperbolicFunctions<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.ILogarithmicFunctions<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IPowerFunctions<TSelf>, System.Numerics.IRootFunctions<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.ITrigonometricFunctions<TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryFloatingPointIeee754<TSelf>?
     {
     }
-    public partial interface IBinaryInteger<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBinaryNumber<TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IShiftOperators<TSelf, int, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryInteger<TSelf>
+    public partial interface IBinaryInteger<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBinaryNumber<TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IShiftOperators<TSelf, int, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryInteger<TSelf>?
     {
         static virtual (TSelf Quotient, TSelf Remainder) DivRem(TSelf left, TSelf right) { throw null; }
         int GetByteCount();
@@ -10257,42 +10257,42 @@ public partial interface IBinaryInteger<TSelf> : System.IComparable, System.ICom
         int WriteLittleEndian(byte[] destination, int startIndex) { throw null; }
         int WriteLittleEndian(System.Span<byte> destination) { throw null; }
     }
-    public partial interface IBinaryNumber<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryNumber<TSelf>
+    public partial interface IBinaryNumber<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IBitwiseOperators<TSelf, TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IBinaryNumber<TSelf>?
     {
         static virtual TSelf AllBitsSet { get { throw null; } }
         static abstract bool IsPow2(TSelf value);
         static abstract TSelf Log2(TSelf value);
     }
-    public partial interface IBitwiseOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IBitwiseOperators<TSelf, TOther, TResult>
+    public partial interface IBitwiseOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IBitwiseOperators<TSelf, TOther, TResult>?
     {
         static abstract TResult operator &(TSelf left, TOther right);
         static abstract TResult operator |(TSelf left, TOther right);
         static abstract TResult operator ^(TSelf left, TOther right);
         static abstract TResult operator ~(TSelf value);
     }
-    public partial interface IComparisonOperators<TSelf, TOther, TResult> : System.Numerics.IEqualityOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IComparisonOperators<TSelf, TOther, TResult>
+    public partial interface IComparisonOperators<TSelf, TOther, TResult> : System.Numerics.IEqualityOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IComparisonOperators<TSelf, TOther, TResult>?
     {
         static abstract TResult operator >(TSelf left, TOther right);
         static abstract TResult operator >=(TSelf left, TOther right);
         static abstract TResult operator <(TSelf left, TOther right);
         static abstract TResult operator <=(TSelf left, TOther right);
     }
-    public partial interface IDecrementOperators<TSelf> where TSelf : System.Numerics.IDecrementOperators<TSelf>
+    public partial interface IDecrementOperators<TSelf> where TSelf : System.Numerics.IDecrementOperators<TSelf>?
     {
         static virtual TSelf operator checked --(TSelf value) { throw null; }
         static abstract TSelf operator --(TSelf value);
     }
-    public partial interface IDivisionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IDivisionOperators<TSelf, TOther, TResult>
+    public partial interface IDivisionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IDivisionOperators<TSelf, TOther, TResult>?
     {
         static virtual TResult operator checked /(TSelf left, TOther right) { throw null; }
         static abstract TResult operator /(TSelf left, TOther right);
     }
-    public partial interface IEqualityOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IEqualityOperators<TSelf, TOther, TResult>
+    public partial interface IEqualityOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IEqualityOperators<TSelf, TOther, TResult>?
     {
-        static abstract TResult operator ==(TSelf left, TOther right);
-        static abstract TResult operator !=(TSelf left, TOther right);
+        static abstract TResult operator ==(TSelf? left, TOther? right);
+        static abstract TResult operator !=(TSelf? left, TOther? right);
     }
-    public partial interface IExponentialFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IExponentialFunctions<TSelf>
+    public partial interface IExponentialFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IExponentialFunctions<TSelf>?
     {
         static abstract TSelf Exp(TSelf x);
         static abstract TSelf Exp10(TSelf x);
@@ -10301,13 +10301,13 @@ public partial interface IExponentialFunctions<TSelf> : System.Numerics.IFloatin
         static virtual TSelf Exp2M1(TSelf x) { throw null; }
         static virtual TSelf ExpM1(TSelf x) { throw null; }
     }
-    public partial interface IFloatingPointConstants<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IFloatingPointConstants<TSelf>
+    public partial interface IFloatingPointConstants<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IFloatingPointConstants<TSelf>?
     {
         static abstract TSelf E { get; }
         static abstract TSelf Pi { get; }
         static abstract TSelf Tau { get; }
     }
-    public partial interface IFloatingPointIeee754<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IExponentialFunctions<TSelf>, System.Numerics.IFloatingPoint<TSelf>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IHyperbolicFunctions<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.ILogarithmicFunctions<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IPowerFunctions<TSelf>, System.Numerics.IRootFunctions<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.ITrigonometricFunctions<TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IFloatingPointIeee754<TSelf>
+    public partial interface IFloatingPointIeee754<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IExponentialFunctions<TSelf>, System.Numerics.IFloatingPoint<TSelf>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IHyperbolicFunctions<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.ILogarithmicFunctions<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.IPowerFunctions<TSelf>, System.Numerics.IRootFunctions<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.ITrigonometricFunctions<TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IFloatingPointIeee754<TSelf>?
     {
         static abstract TSelf Epsilon { get; }
         static abstract TSelf NaN { get; }
@@ -10325,7 +10325,7 @@ public partial interface IFloatingPointIeee754<TSelf> : System.IComparable, Syst
         static virtual TSelf ReciprocalSqrtEstimate(TSelf x) { throw null; }
         static abstract TSelf ScaleB(TSelf x, int n);
     }
-    public partial interface IFloatingPoint<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IFloatingPoint<TSelf>
+    public partial interface IFloatingPoint<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumber<TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISignedNumber<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.IFloatingPoint<TSelf>?
     {
         static virtual TSelf Ceiling(TSelf x) { throw null; }
         static virtual TSelf Floor(TSelf x) { throw null; }
@@ -10355,7 +10355,7 @@ public partial interface IFloatingPoint<TSelf> : System.IComparable, System.ICom
         int WriteSignificandLittleEndian(byte[] destination, int startIndex) { throw null; }
         int WriteSignificandLittleEndian(System.Span<byte> destination) { throw null; }
     }
-    public partial interface IHyperbolicFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IHyperbolicFunctions<TSelf>
+    public partial interface IHyperbolicFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IHyperbolicFunctions<TSelf>?
     {
         static abstract TSelf Acosh(TSelf x);
         static abstract TSelf Asinh(TSelf x);
@@ -10364,12 +10364,12 @@ public partial interface IHyperbolicFunctions<TSelf> : System.Numerics.IFloating
         static abstract TSelf Sinh(TSelf x);
         static abstract TSelf Tanh(TSelf x);
     }
-    public partial interface IIncrementOperators<TSelf> where TSelf : System.Numerics.IIncrementOperators<TSelf>
+    public partial interface IIncrementOperators<TSelf> where TSelf : System.Numerics.IIncrementOperators<TSelf>?
     {
         static virtual TSelf operator checked ++(TSelf value) { throw null; }
         static abstract TSelf operator ++(TSelf value);
     }
-    public partial interface ILogarithmicFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ILogarithmicFunctions<TSelf>
+    public partial interface ILogarithmicFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ILogarithmicFunctions<TSelf>?
     {
         static abstract TSelf Log(TSelf x);
         static abstract TSelf Log(TSelf x, TSelf newBase);
@@ -10379,33 +10379,42 @@ public partial interface ILogarithmicFunctions<TSelf> : System.Numerics.IFloatin
         static virtual TSelf Log2P1(TSelf x) { throw null; }
         static virtual TSelf LogP1(TSelf x) { throw null; }
     }
-    public partial interface IMinMaxValue<TSelf> where TSelf : System.Numerics.IMinMaxValue<TSelf>
+    public partial interface IMinMaxValue<TSelf> where TSelf : System.Numerics.IMinMaxValue<TSelf>?
     {
         static abstract TSelf MaxValue { get; }
         static abstract TSelf MinValue { get; }
     }
-    public partial interface IModulusOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IModulusOperators<TSelf, TOther, TResult>
+    public partial interface IModulusOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IModulusOperators<TSelf, TOther, TResult>?
     {
         static abstract TResult operator %(TSelf left, TOther right);
     }
-    public partial interface IMultiplicativeIdentity<TSelf, TResult> where TSelf : System.Numerics.IMultiplicativeIdentity<TSelf, TResult>
+    public partial interface IMultiplicativeIdentity<TSelf, TResult> where TSelf : System.Numerics.IMultiplicativeIdentity<TSelf, TResult>?
     {
         static abstract TResult MultiplicativeIdentity { get; }
     }
-    public partial interface IMultiplyOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IMultiplyOperators<TSelf, TOther, TResult>
+    public partial interface IMultiplyOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IMultiplyOperators<TSelf, TOther, TResult>?
     {
         static virtual TResult operator checked *(TSelf left, TOther right) { throw null; }
         static abstract TResult operator *(TSelf left, TOther right);
     }
-    public partial interface INumberBase<TSelf> : System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.INumberBase<TSelf>
+    public partial interface INumberBase<TSelf> : System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.INumberBase<TSelf>?
     {
         static abstract TSelf One { get; }
         static abstract int Radix { get; }
         static abstract TSelf Zero { get; }
         static abstract TSelf Abs(TSelf value);
-        static virtual TSelf CreateChecked<TOther>(TOther value) where TOther : System.Numerics.INumberBase<TOther> { throw null; }
-        static virtual TSelf CreateSaturating<TOther>(TOther value) where TOther : System.Numerics.INumberBase<TOther> { throw null; }
-        static virtual TSelf CreateTruncating<TOther>(TOther value) where TOther : System.Numerics.INumberBase<TOther> { throw null; }
+        static virtual TSelf CreateChecked<TOther>(TOther value)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther> { throw null; }
+#nullable restore
+        static virtual TSelf CreateSaturating<TOther>(TOther value)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther> { throw null; }
+#nullable restore
+        static virtual TSelf CreateTruncating<TOther>(TOther value)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther> { throw null; }
+#nullable restore
         static abstract bool IsCanonical(TSelf value);
         static abstract bool IsComplexNumber(TSelf value);
         static abstract bool IsEvenInteger(TSelf value);
@@ -10429,16 +10438,34 @@ public partial interface INumberBase<TSelf> : System.IEquatable<TSelf>, System.I
         static abstract TSelf MinMagnitudeNumber(TSelf x, TSelf y);
         static abstract TSelf Parse(System.ReadOnlySpan<char> s, System.Globalization.NumberStyles style, System.IFormatProvider? provider);
         static abstract TSelf Parse(string s, System.Globalization.NumberStyles style, System.IFormatProvider? provider);
-        protected static abstract bool TryConvertFromChecked<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TSelf? result) where TOther : System.Numerics.INumberBase<TOther>;
-        protected static abstract bool TryConvertFromSaturating<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TSelf? result) where TOther : System.Numerics.INumberBase<TOther>;
-        protected static abstract bool TryConvertFromTruncating<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TSelf? result) where TOther : System.Numerics.INumberBase<TOther>;
-        protected static abstract bool TryConvertToChecked<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther? result) where TOther : System.Numerics.INumberBase<TOther>;
-        protected static abstract bool TryConvertToSaturating<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther? result) where TOther : System.Numerics.INumberBase<TOther>;
-        protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out TOther? result) where TOther : System.Numerics.INumberBase<TOther>;
+        protected static abstract bool TryConvertFromChecked<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TSelf result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
+        protected static abstract bool TryConvertFromSaturating<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TSelf result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
+        protected static abstract bool TryConvertFromTruncating<TOther>(TOther value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TSelf result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
+        protected static abstract bool TryConvertToChecked<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TOther result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
+        protected static abstract bool TryConvertToSaturating<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TOther result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
+        protected static abstract bool TryConvertToTruncating<TOther>(TSelf value, [System.Diagnostics.CodeAnalysis.MaybeNullWhen(false)] out TOther result)
+#nullable disable
+            where TOther : System.Numerics.INumberBase<TOther>;
+#nullable restore
         static abstract bool TryParse(System.ReadOnlySpan<char> s, System.Globalization.NumberStyles style, System.IFormatProvider? provider, out TSelf result);
         static abstract bool TryParse([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] string? s, System.Globalization.NumberStyles style, System.IFormatProvider? provider, out TSelf result);
     }
-    public partial interface INumber<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.INumber<TSelf>
+    public partial interface INumber<TSelf> : System.IComparable, System.IComparable<TSelf>, System.IEquatable<TSelf>, System.IFormattable, System.IParsable<TSelf>, System.ISpanFormattable, System.ISpanParsable<TSelf>, System.Numerics.IAdditionOperators<TSelf, TSelf, TSelf>, System.Numerics.IAdditiveIdentity<TSelf, TSelf>, System.Numerics.IComparisonOperators<TSelf, TSelf, bool>, System.Numerics.IDecrementOperators<TSelf>, System.Numerics.IDivisionOperators<TSelf, TSelf, TSelf>, System.Numerics.IEqualityOperators<TSelf, TSelf, bool>, System.Numerics.IIncrementOperators<TSelf>, System.Numerics.IModulusOperators<TSelf, TSelf, TSelf>, System.Numerics.IMultiplicativeIdentity<TSelf, TSelf>, System.Numerics.IMultiplyOperators<TSelf, TSelf, TSelf>, System.Numerics.INumberBase<TSelf>, System.Numerics.ISubtractionOperators<TSelf, TSelf, TSelf>, System.Numerics.IUnaryNegationOperators<TSelf, TSelf>, System.Numerics.IUnaryPlusOperators<TSelf, TSelf> where TSelf : System.Numerics.INumber<TSelf>?
     {
         static virtual TSelf Clamp(TSelf value, TSelf min, TSelf max) { throw null; }
         static virtual TSelf CopySign(TSelf value, TSelf sign) { throw null; }
@@ -10448,33 +10475,33 @@ public partial interface INumber<TSelf> : System.IComparable, System.IComparable
         static virtual TSelf MinNumber(TSelf x, TSelf y) { throw null; }
         static virtual int Sign(TSelf value) { throw null; }
     }
-    public partial interface IPowerFunctions<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IPowerFunctions<TSelf>
+    public partial interface IPowerFunctions<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IPowerFunctions<TSelf>?
     {
         static abstract TSelf Pow(TSelf x, TSelf y);
     }
-    public partial interface IRootFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IRootFunctions<TSelf>
+    public partial interface IRootFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IRootFunctions<TSelf>?
     {
         static abstract TSelf Cbrt(TSelf x);
         static abstract TSelf Hypot(TSelf x, TSelf y);
         static abstract TSelf RootN(TSelf x, int n);
         static abstract TSelf Sqrt(TSelf x);
     }
-    public partial interface IShiftOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IShiftOperators<TSelf, TOther, TResult>
+    public partial interface IShiftOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.IShiftOperators<TSelf, TOther, TResult>?
     {
         static abstract TResult operator <<(TSelf value, TOther shiftAmount);
         static abstract TResult operator >>(TSelf value, TOther shiftAmount);
         static abstract TResult operator >>>(TSelf value, TOther shiftAmount);
     }
-    public partial interface ISignedNumber<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ISignedNumber<TSelf>
+    public partial interface ISignedNumber<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ISignedNumber<TSelf>?
     {
         static abstract TSelf NegativeOne { get; }
     }
-    public partial interface ISubtractionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.ISubtractionOperators<TSelf, TOther, TResult>
+    public partial interface ISubtractionOperators<TSelf, TOther, TResult> where TSelf : System.Numerics.ISubtractionOperators<TSelf, TOther, TResult>?
     {
         static virtual TResult operator checked -(TSelf left, TOther right) { throw null; }
         static abstract TResult operator -(TSelf left, TOther right);
     }
-    public partial interface ITrigonometricFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ITrigonometricFunctions<TSelf>
+    public partial interface ITrigonometricFunctions<TSelf> : System.Numerics.IFloatingPointConstants<TSelf>, System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.ITrigonometricFunctions<TSelf>?
     {
         static abstract TSelf Acos(TSelf x);
         static abstract TSelf AcosPi(TSelf x);
@@ -10491,16 +10518,16 @@ public partial interface ITrigonometricFunctions<TSelf> : System.Numerics.IFloat
         static abstract TSelf Tan(TSelf x);
         static abstract TSelf TanPi(TSelf x);
     }
-    public partial interface IUnaryNegationOperators<TSelf, TResult> where TSelf : System.Numerics.IUnaryNegationOperators<TSelf, TResult>
+    public partial interface IUnaryNegationOperators<TSelf, TResult> where TSelf : System.Numerics.IUnaryNegationOperators<TSelf, TResult>?
     {
         static virtual TResult operator checked -(TSelf value) { throw null; }
         static abstract TResult operator -(TSelf value);
     }
-    public partial interface IUnaryPlusOperators<TSelf, TResult> where TSelf : System.Numerics.IUnaryPlusOperators<TSelf, TResult>
+    public partial interface IUnaryPlusOperators<TSelf, TResult> where TSelf : System.Numerics.IUnaryPlusOperators<TSelf, TResult>?
     {
         static abstract TResult operator +(TSelf value);
     }
-    public partial interface IUnsignedNumber<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IUnsignedNumber<TSelf>
+    public partial interface IUnsignedNumber<TSelf> : System.Numerics.INumberBase<TSelf> where TSelf : System.Numerics.IUnsignedNumber<TSelf>?
     {
     }
 }
diff --git a/src/libraries/System.Runtime/tests/System/Numerics/GenericMathDimHelpers.cs b/src/libraries/System.Runtime/tests/System/Numerics/GenericMathDimHelpers.cs
index d6b34be311441..c072ce36ad29f 100644
--- a/src/libraries/System.Runtime/tests/System/Numerics/GenericMathDimHelpers.cs
+++ b/src/libraries/System.Runtime/tests/System/Numerics/GenericMathDimHelpers.cs
@@ -60,9 +60,9 @@ private BinaryNumberDimHelper(int value)
         static BinaryNumberDimHelper INumberBase<BinaryNumberDimHelper>.Parse(string s, NumberStyles style, IFormatProvider? provider) => throw new NotImplementedException();
         static BinaryNumberDimHelper ISpanParsable<BinaryNumberDimHelper>.Parse(ReadOnlySpan<char> s, IFormatProvider? provider) => throw new NotImplementedException();
         static BinaryNumberDimHelper IParsable<BinaryNumberDimHelper>.Parse(string s, IFormatProvider? provider) => throw new NotImplementedException();
-        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToChecked<TOther>(BinaryNumberDimHelper value, out TOther? result) where TOther : default => throw new NotImplementedException();
-        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToSaturating<TOther>(BinaryNumberDimHelper value, out TOther? result) where TOther : default => throw new NotImplementedException();
-        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToTruncating<TOther>(BinaryNumberDimHelper value, out TOther? result) where TOther : default => throw new NotImplementedException();
+        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToChecked<TOther>(BinaryNumberDimHelper value, out TOther result) where TOther : default => throw new NotImplementedException();
+        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToSaturating<TOther>(BinaryNumberDimHelper value, out TOther result) where TOther : default => throw new NotImplementedException();
+        static bool INumberBase<BinaryNumberDimHelper>.TryConvertToTruncating<TOther>(BinaryNumberDimHelper value, out TOther result) where TOther : default => throw new NotImplementedException();
         static bool INumberBase<BinaryNumberDimHelper>.TryParse(ReadOnlySpan<char> s, NumberStyles style, IFormatProvider? provider, out BinaryNumberDimHelper result) => throw new NotImplementedException();
         static bool INumberBase<BinaryNumberDimHelper>.TryParse(string? s, NumberStyles style, IFormatProvider? provider, out BinaryNumberDimHelper result) => throw new NotImplementedException();
         static bool ISpanParsable<BinaryNumberDimHelper>.TryParse(ReadOnlySpan<char> s, IFormatProvider? provider, out BinaryNumberDimHelper result) => throw new NotImplementedException();