semipperm.gi: fix RankOfPartialPermSemigroup for groups

Resolves #3037.
gap-system · Nov 24, 2018 · 16ec90c · 16ec90c
1 parent 986d08a
commit 16ec90c
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/lib/semipperm.gi b/lib/semipperm.gi
@@ -94,17 +94,17 @@ InstallMethod(CodegreeOfPartialPermSemigroup,
 s-> DegreeOfPartialPermSemigroup(s));
 
 InstallMethod(RankOfPartialPermSemigroup,
-"for a partial perm semigroup",
+"for a partial perm semigroup with generators of semigroup",
 [IsPartialPermSemigroup and HasGeneratorsOfSemigroup],
 S -> RankOfPartialPermCollection(GeneratorsOfSemigroup(S)));
 
 InstallMethod(RankOfPartialPermSemigroup,
-"for a partial perm semigroup",
-[IsPartialPermSemigroup and HasGeneratorsOfGroup],
-S -> RankOfPartialPermCollection(GeneratorsOfGroup(S)));
+"for a partial perm monoid",
+[IsPartialPermMonoid],
+S -> RankOfPartialPerm(One(S)));
 
 InstallMethod(RankOfPartialPermCollection,
-"for a partial perm semigroup",
+"for a partial perm semigroup with generators of semigroup",
 [IsPartialPermSemigroup and HasGeneratorsOfSemigroup],
 s-> RankOfPartialPermCollection(GeneratorsOfSemigroup(s)));
 

diff --git a/tst/testinstall/semipperm.tst b/tst/testinstall/semipperm.tst
@@ -86,6 +86,9 @@ gap> RankOfPartialPermSemigroup(S);
 gap> S := Group(PartialPerm([]));;
 gap> RankOfPartialPermSemigroup(S);
 0
+gap> S := Group([], PartialPerm([1, 2]));;
+gap> RankOfPartialPermSemigroup(S);
+2
 
 # Test Domain/ImageOfPartialPermCollection/Semigroup
 gap> S := Semigroup(PartialPerm([1, 2, 3], [4, 5, 11]),