From 526e120df509609298e13c169e78225f8b65ed3e Mon Sep 17 00:00:00 2001
From: Max Horn <max@quendi.de>
Date: Wed, 15 May 2019 17:13:43 +0200
Subject: [PATCH] Add a bunch of trivial implications

This makes various "hidden" implications created by DeclareProperty
explicit, thus fixing a bunch of warnings that show up if one starts
the upcoming GAP 4.11 with the `-N` command line option, and then
loads this package.

For some information on the background of this, see also
<https://github.com/gap-system/gap/issues/1649> and
<https://github.com/gap-system/gap/issues/2336>
---
 lib/cong.gd | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/cong.gd b/lib/cong.gd
index 4c39f71..7ebada3 100644
--- a/lib/cong.gd
+++ b/lib/cong.gd
@@ -38,6 +38,7 @@ DeclareCategory( "IsCongruenceSubgroup", IsMatrixGroup );
 ##               [   N  1+N ]
 ##
 DeclareProperty( "IsPrincipalCongruenceSubgroup", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsPrincipalCongruenceSubgroup);
 
 
 #############################################################################
@@ -49,6 +50,7 @@ DeclareProperty( "IsPrincipalCongruenceSubgroup", IsCongruenceSubgroup );
 ##               [   N    * ]
 ##
 DeclareProperty( "IsCongruenceSubgroupGamma0", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsCongruenceSubgroupGamma0);
 
 
 #############################################################################
@@ -60,6 +62,7 @@ DeclareProperty( "IsCongruenceSubgroupGamma0", IsCongruenceSubgroup );
 ##               [   *    * ]
 ##
 DeclareProperty( "IsCongruenceSubgroupGammaUpper0", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsCongruenceSubgroupGammaUpper0);
 
 
 #############################################################################
@@ -71,6 +74,7 @@ DeclareProperty( "IsCongruenceSubgroupGammaUpper0", IsCongruenceSubgroup );
 ##               [   N  1+N ]
 ##
 DeclareProperty( "IsCongruenceSubgroupGamma1", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsCongruenceSubgroupGamma1);
 
 
 #############################################################################
@@ -82,6 +86,7 @@ DeclareProperty( "IsCongruenceSubgroupGamma1", IsCongruenceSubgroup );
 ##               [   *  1+N ]
 ##
 DeclareProperty( "IsCongruenceSubgroupGammaUpper1", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsCongruenceSubgroupGammaUpper1);
 
 
 #############################################################################
@@ -93,6 +98,7 @@ DeclareProperty( "IsCongruenceSubgroupGammaUpper1", IsCongruenceSubgroup );
 ##               [   N  1+N ]
 ##
 DeclareProperty( "IsCongruenceSubgroupGammaMN", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsCongruenceSubgroupGammaMN);
 
 
 #############################################################################
@@ -106,6 +112,7 @@ DeclareProperty( "IsCongruenceSubgroupGammaMN", IsCongruenceSubgroup );
 ## CongruenceSubgroupGamma^1 and CongruenceSubgroupGammaMN
 ##
 DeclareProperty( "IsIntersectionOfCongruenceSubgroups", IsCongruenceSubgroup );
+InstallTrueMethod(IsCongruenceSubgroup, IsIntersectionOfCongruenceSubgroups);
 
 
 #############################################################################