Fix incorrect IsFinitelyGeneratedMonoid method

A finite generating set implies finite generation; but an infinite generating set does not mean that there cannot be a finite one, too.
gap-system · Mar 22, 2018 · 8a338d7 · 8a338d7
1 parent 1c4dd9d
commit 8a338d7
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diff --git a/lib/monofree.gi b/lib/monofree.gi
@@ -260,6 +260,7 @@ InstallGlobalFunction( FreeMonoid, function( arg )
  SetIsTrivial( M, false );
  SetIsFinite( M, false );
  SetIsCommutative(M, false );
+ SetIsFinitelyGeneratedMonoid(M, false);
  fi;
 
  SetIsFreeMonoid( M, true);

diff --git a/lib/monoid.gi b/lib/monoid.gi
@@ -304,7 +304,10 @@ end);
 InstallMethod( IsFinitelyGeneratedMonoid, "for a monoid",
  [ IsMonoid and HasGeneratorsOfMonoid ],
 function(M)
- return IsFinite(GeneratorsOfMonoid(M));
+ if IsFinite(GeneratorsOfMonoid(M)) then
+ return true;
+ fi;
+ TryNextMethod();
 end);