diff --git a/lib/pure/collections/sequtils.nim b/lib/pure/collections/sequtils.nim
index 71558fe0dd6a..a7e3920269ef 100644
--- a/lib/pure/collections/sequtils.nim
+++ b/lib/pure/collections/sequtils.nim
@@ -110,12 +110,12 @@ macro evalOnceAs(expAlias, exp: untyped,
     newProc(name = genSym(nskTemplate, $expAlias), params = [getType(untyped)],
       body = val, procType = nnkTemplateDef))
 
-proc concat*[T](seqs: varargs[seq[T]]): seq[T] =
+func concat*[T](seqs: varargs[seq[T]]): seq[T] =
   ## Takes several sequences' items and returns them inside a new sequence.
   ## All sequences must be of the same type.
   ##
   ## See also:
-  ## * `distribute proc<#distribute,seq[T],Positive>`_ for a reverse
+  ## * `distribute func<#distribute,seq[T],Positive>`_ for a reverse
   ##   operation
   ##
   runnableExamples:
@@ -135,7 +135,7 @@ proc concat*[T](seqs: varargs[seq[T]]): seq[T] =
       result[i] = itm
       inc(i)
 
-proc count*[T](s: openArray[T], x: T): int =
+func count*[T](s: openArray[T], x: T): int =
   ## Returns the number of occurrences of the item `x` in the container `s`.
   ##
   runnableExamples:
@@ -150,7 +150,7 @@ proc count*[T](s: openArray[T], x: T): int =
     if itm == x:
       inc result
 
-proc cycle*[T](s: openArray[T], n: Natural): seq[T] =
+func cycle*[T](s: openArray[T], n: Natural): seq[T] =
   ## Returns a new sequence with the items of the container `s` repeated
   ## `n` times.
   ## `n` must be a non-negative number (zero or more).
@@ -168,7 +168,7 @@ proc cycle*[T](s: openArray[T], n: Natural): seq[T] =
       result[o] = e
       inc o
 
-proc repeat*[T](x: T, n: Natural): seq[T] =
+func repeat*[T](x: T, n: Natural): seq[T] =
   ## Returns a new sequence with the item `x` repeated `n` times.
   ## `n` must be a non-negative number (zero or more).
   ##
@@ -181,7 +181,7 @@ proc repeat*[T](x: T, n: Natural): seq[T] =
   for i in 0 ..< n:
     result[i] = x
 
-proc deduplicate*[T](s: openArray[T], isSorted: bool = false): seq[T] =
+func deduplicate*[T](s: openArray[T], isSorted: bool = false): seq[T] =
   ## Returns a new sequence without duplicates.
   ##
   ## Setting the optional argument ``isSorted`` to ``true`` (default: false)
@@ -209,7 +209,7 @@ proc deduplicate*[T](s: openArray[T], isSorted: bool = false): seq[T] =
       for itm in items(s):
         if not result.contains(itm): result.add(itm)
 
-proc minIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
+func minIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
   ## Returns the index of the minimum value of `s`.
   ## ``T`` needs to have a ``<`` operator.
   runnableExamples:
@@ -226,7 +226,7 @@ proc minIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
   for i in 1..high(s):
     if s[i] < s[result]: result = i
 
-proc maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
+func maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
   ## Returns the index of the maximum value of `s`.
   ## ``T`` needs to have a ``<`` operator.
   runnableExamples:
@@ -245,7 +245,7 @@ proc maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} =
 
 
 template zipImpl(s1, s2, retType: untyped): untyped =
-  proc zip*[S, T](s1: openArray[S], s2: openArray[T]): retType =
+  func zip*[S, T](s1: openArray[S], s2: openArray[T]): retType =
     ## Returns a new sequence with a combination of the two input containers.
     ##
     ## The input containers can be of different types.
@@ -288,7 +288,7 @@ when (NimMajor, NimMinor) <= (1, 0):
 else:
   zipImpl(s1, s2, seq[(S, T)])
 
-proc unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} =
+func unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} =
   ## Returns a tuple of two sequences split out from a sequence of 2-field tuples.
   runnableExamples:
     let
@@ -303,19 +303,19 @@ proc unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} =
     result[0][i] = s[i][0]
     result[1][i] = s[i][1]
 
-proc distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] =
+func distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] =
   ## Splits and distributes a sequence `s` into `num` sub-sequences.
   ##
   ## Returns a sequence of `num` sequences. For *some* input values this is the
-  ## inverse of the `concat <#concat,varargs[seq[T]]>`_ proc.
+  ## inverse of the `concat <#concat,varargs[seq[T]]>`_ func.
   ## The input sequence `s` can be empty, which will produce
   ## `num` empty sequences.
   ##
   ## If `spread` is false and the length of `s` is not a multiple of `num`, the
-  ## proc will max out the first sub-sequence with ``1 + len(s) div num``
+  ## func will max out the first sub-sequence with ``1 + len(s) div num``
   ## entries, leaving the remainder of elements to the last sequence.
   ##
-  ## On the other hand, if `spread` is true, the proc will distribute evenly
+  ## On the other hand, if `spread` is true, the func will distribute evenly
   ## the remainder of the division across all sequences, which makes the result
   ## more suited to multithreading where you are passing equal sized work units
   ## to a thread pool and want to maximize core usage.
@@ -360,7 +360,7 @@ proc distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] =
         result[i].add(s[g])
       first = last
 
-proc map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}):
+func map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}):
                                                             seq[S]{.inline.} =
   ## Returns a new sequence with the results of `op` proc applied to every
   ## item in the container `s`.
@@ -374,7 +374,7 @@ proc map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}):
   ## See also:
   ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_
   ## * `mapIt template<#mapIt.t,typed,untyped>`_
-  ## * `apply proc<#apply,openArray[T],proc(T)_2>`_ for the in-place version
+  ## * `apply func<#apply,openArray[T],proc(T)_2>`_ for the in-place version
   ##
   runnableExamples:
     let
@@ -386,7 +386,7 @@ proc map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}):
   for i in 0 ..< s.len:
     result[i] = op(s[i])
 
-proc apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.})
+func apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.})
                                                               {.inline.} =
   ## Applies `op` to every item in `s` modifying it directly.
   ##
@@ -397,7 +397,7 @@ proc apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.})
   ##
   ## See also:
   ## * `applyIt template<#applyIt.t,untyped,untyped>`_
-  ## * `map proc<#map,openArray[T],proc(T)>`_
+  ## * `map func<#map,openArray[T],proc(T)>`_
   ##
   runnableExamples:
     var a = @["1", "2", "3", "4"]
@@ -406,7 +406,7 @@ proc apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.})
 
   for i in 0 ..< s.len: op(s[i])
 
-proc apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.})
+func apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.})
                                                               {.inline.} =
   ## Applies `op` to every item in `s` modifying it directly.
   ##
@@ -417,7 +417,7 @@ proc apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.})
   ##
   ## See also:
   ## * `applyIt template<#applyIt.t,untyped,untyped>`_
-  ## * `map proc<#map,openArray[T],proc(T)>`_
+  ## * `map func<#map,openArray[T],proc(T)>`_
   ##
   runnableExamples:
     var a = @["1", "2", "3", "4"]
@@ -426,7 +426,7 @@ proc apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.})
 
   for i in 0 ..< s.len: s[i] = op(s[i])
 
-proc apply*[T](s: openArray[T], op: proc (x: T) {.closure.}) {.inline, since: (1, 3).} =
+func apply*[T](s: openArray[T], op: proc (x: T) {.closure.}) {.inline, since: (1, 3).} =
   ## Same as `apply` but for proc that do not return and do not mutate `s` directly.
   runnableExamples: apply([0, 1, 2, 3, 4], proc(item: int) = echo item)
   for i in 0 ..< s.len: op(s[i])
@@ -440,7 +440,7 @@ iterator filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): T =
   ##
   ## See also:
   ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_
-  ## * `fliter proc<#filter,openArray[T],proc(T)>`_
+  ## * `fliter func<#filter,openArray[T],proc(T)>`_
   ## * `filterIt template<#filterIt.t,untyped,untyped>`_
   ##
   runnableExamples:
@@ -454,7 +454,7 @@ iterator filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): T =
     if pred(s[i]):
       yield s[i]
 
-proc filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T]
+func filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T]
                                                                   {.inline.} =
   ## Returns a new sequence with all the items of `s` that fulfilled the
   ## predicate `pred` (function that returns a `bool`).
@@ -466,7 +466,7 @@ proc filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T]
   ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_
   ## * `filterIt template<#filterIt.t,untyped,untyped>`_
   ## * `filter iterator<#filter.i,openArray[T],proc(T)>`_
-  ## * `keepIf proc<#keepIf,seq[T],proc(T)>`_ for the in-place version
+  ## * `keepIf func<#keepIf,seq[T],proc(T)>`_ for the in-place version
   ##
   runnableExamples:
     let
@@ -481,19 +481,19 @@ proc filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T]
     if pred(s[i]):
       result.add(s[i])
 
-proc keepIf*[T](s: var seq[T], pred: proc(x: T): bool {.closure.})
+func keepIf*[T](s: var seq[T], pred: proc(x: T): bool {.closure.})
                                                                 {.inline.} =
   ## Keeps the items in the passed sequence `s` if they fulfilled the
   ## predicate `pred` (function that returns a `bool`).
   ##
   ## Note that `s` must be declared as a ``var``.
   ##
-  ## Similar to the `filter proc<#filter,openArray[T],proc(T)>`_,
+  ## Similar to the `filter func<#filter,openArray[T],proc(T)>`_,
   ## but modifies the sequence directly.
   ##
   ## See also:
   ## * `keepItIf template<#keepItIf.t,seq,untyped>`_
-  ## * `filter proc<#filter,openArray[T],proc(T)>`_
+  ## * `filter func<#filter,openArray[T],proc(T)>`_
   ##
   runnableExamples:
     var floats = @[13.0, 12.5, 5.8, 2.0, 6.1, 9.9, 10.1]
@@ -511,7 +511,7 @@ proc keepIf*[T](s: var seq[T], pred: proc(x: T): bool {.closure.})
       inc(pos)
   setLen(s, pos)
 
-proc delete*[T](s: var seq[T]; first, last: Natural) =
+func delete*[T](s: var seq[T]; first, last: Natural) =
   ## Deletes in the items of a sequence `s` at positions ``first..last``
   ## (including both ends of a range).
   ## This modifies `s` itself, it does not return a copy.
@@ -536,7 +536,7 @@ proc delete*[T](s: var seq[T]; first, last: Natural) =
     inc(j)
   setLen(s, newLen)
 
-proc insert*[T](dest: var seq[T], src: openArray[T], pos = 0) =
+func insert*[T](dest: var seq[T], src: openArray[T], pos = 0) =
   ## Inserts items from `src` into `dest` at position `pos`. This modifies
   ## `dest` itself, it does not return a copy.
   ##
@@ -574,7 +574,7 @@ template filterIt*(s, pred: untyped): untyped =
   ## Returns a new sequence with all the items of `s` that fulfilled the
   ## predicate `pred`.
   ##
-  ## Unlike the `filter proc<#filter,openArray[T],proc(T)>`_ and
+  ## Unlike the `filter func<#filter,openArray[T],proc(T)>`_ and
   ## `filter iterator<#filter.i,openArray[T],proc(T)>`_,
   ## the predicate needs to be an expression using the ``it`` variable
   ## for testing, like: ``filterIt("abcxyz", it == 'x')``.
@@ -584,7 +584,7 @@ template filterIt*(s, pred: untyped): untyped =
   ##
   ## See also:
   ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_
-  ## * `fliter proc<#filter,openArray[T],proc(T)>`_
+  ## * `fliter func<#filter,openArray[T],proc(T)>`_
   ## * `filter iterator<#filter.i,openArray[T],proc(T)>`_
   ##
   runnableExamples:
@@ -604,12 +604,12 @@ template keepItIf*(varSeq: seq, pred: untyped) =
   ## Keeps the items in the passed sequence (must be declared as a ``var``)
   ## if they fulfilled the predicate.
   ##
-  ## Unlike the `keepIf proc<#keepIf,seq[T],proc(T)>`_,
+  ## Unlike the `keepIf func<#keepIf,seq[T],proc(T)>`_,
   ## the predicate needs to be an expression using
   ## the ``it`` variable for testing, like: ``keepItIf("abcxyz", it == 'x')``.
   ##
   ## See also:
-  ## * `keepIf proc<#keepIf,seq[T],proc(T)>`_
+  ## * `keepIf func<#keepIf,seq[T],proc(T)>`_
   ## * `filterIt template<#filterIt.t,untyped,untyped>`_
   ##
   runnableExamples:
@@ -648,13 +648,13 @@ since (1, 1):
       if pred: result += 1
     result
 
-proc all*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool =
+func all*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool =
   ## Iterates through a container and checks if every item fulfills the
   ## predicate.
   ##
   ## See also:
   ## * `allIt template<#allIt.t,untyped,untyped>`_
-  ## * `any proc<#any,openArray[T],proc(T)>`_
+  ## * `any func<#any,openArray[T],proc(T)>`_
   ##
   runnableExamples:
     let numbers = @[1, 4, 5, 8, 9, 7, 4]
@@ -670,12 +670,12 @@ template allIt*(s, pred: untyped): bool =
   ## Iterates through a container and checks if every item fulfills the
   ## predicate.
   ##
-  ## Unlike the `all proc<#all,openArray[T],proc(T)>`_,
+  ## Unlike the `all func<#all,openArray[T],proc(T)>`_,
   ## the predicate needs to be an expression using
   ## the ``it`` variable for testing, like: ``allIt("abba", it == 'a')``.
   ##
   ## See also:
-  ## * `all proc<#all,openArray[T],proc(T)>`_
+  ## * `all func<#all,openArray[T],proc(T)>`_
   ## * `anyIt template<#anyIt.t,untyped,untyped>`_
   ##
   runnableExamples:
@@ -690,13 +690,13 @@ template allIt*(s, pred: untyped): bool =
       break
   result
 
-proc any*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool =
+func any*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool =
   ## Iterates through a container and checks if some item fulfills the
   ## predicate.
   ##
   ## See also:
   ## * `anyIt template<#anyIt.t,untyped,untyped>`_
-  ## * `all proc<#all,openArray[T],proc(T)>`_
+  ## * `all func<#all,openArray[T],proc(T)>`_
   ##
   runnableExamples:
     let numbers = @[1, 4, 5, 8, 9, 7, 4]
@@ -712,12 +712,12 @@ template anyIt*(s, pred: untyped): bool =
   ## Iterates through a container and checks if some item fulfills the
   ## predicate.
   ##
-  ## Unlike the `any proc<#any,openArray[T],proc(T)>`_,
+  ## Unlike the `any func<#any,openArray[T],proc(T)>`_,
   ## the predicate needs to be an expression using
   ## the ``it`` variable for testing, like: ``anyIt("abba", it == 'a')``.
   ##
   ## See also:
-  ## * `any proc<#any,openArray[T],proc(T)>`_
+  ## * `any func<#any,openArray[T],proc(T)>`_
   ## * `allIt template<#allIt.t,untyped,untyped>`_
   ##
   runnableExamples:
@@ -840,7 +840,7 @@ template foldl*(sequence, operation: untyped): untyped =
       procs = @["proc", "Is", "Also", "Fine"]
 
 
-    proc foo(acc, cur: string): string =
+    func foo(acc, cur: string): string =
       result = acc & cur
 
     assert addition == 25, "Addition is (((5)+9)+11)"
@@ -944,7 +944,7 @@ template mapIt*(s: typed, op: untyped): untyped =
   ##
   ## See also:
   ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_
-  ## * `map proc<#map,openArray[T],proc(T)>`_
+  ## * `map func<#map,openArray[T],proc(T)>`_
   ## * `applyIt template<#applyIt.t,untyped,untyped>`_ for the in-place version
   ##
   runnableExamples:
@@ -1005,14 +1005,14 @@ template mapIt*(s: typed, op: untyped): untyped =
     map(s, f)
 
 template applyIt*(varSeq, op: untyped) =
-  ## Convenience template around the mutable ``apply`` proc to reduce typing.
+  ## Convenience template around the mutable ``apply`` func to reduce typing.
   ##
   ## The template injects the ``it`` variable which you can use directly in an
   ## expression. The expression has to return the same type as the sequence you
   ## are mutating.
   ##
   ## See also:
-  ## * `apply proc<#apply,openArray[T],proc(T)_2>`_
+  ## * `apply func<#apply,openArray[T],proc(T)_2>`_
   ## * `mapIt template<#mapIt.t,typed,untyped>`_
   ##
   runnableExamples:
@@ -1048,7 +1048,7 @@ template newSeqWith*(len: int, init: untyped): untyped =
     result[i] = init
   result
 
-proc mapLitsImpl(constructor: NimNode; op: NimNode; nested: bool;
+func mapLitsImpl(constructor: NimNode; op: NimNode; nested: bool;
                  filter = nnkLiterals): NimNode =
   if constructor.kind in filter:
     result = newNimNode(nnkCall, lineInfoFrom = constructor)
diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 18f91f51602c..faa2f8c715ab 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -16,7 +16,7 @@
 ##
 ## Common usages of sets:
 ## * removing duplicates from a container by converting it with `toHashSet proc
-##   <#toHashSet,openArray[A]>`_ (see also `sequtils.deduplicate proc
+##   <#toHashSet,openArray[A]>`_ (see also `sequtils.deduplicate func
 ##   <sequtils.html#deduplicate,openArray[T],bool>`_)
 ## * membership testing
 ## * mathematical operations on two sets, such as
diff --git a/tests/effects/tstrict_funcs.nim b/tests/effects/tstrict_funcs.nim
index 89ac681086a0..7a0f1ee328d4 100644
--- a/tests/effects/tstrict_funcs.nim
+++ b/tests/effects/tstrict_funcs.nim
@@ -10,6 +10,7 @@ import
   httpcore,
   math,
   nre,
+  sequtils,
   strutils,
   uri