[GAP Forum] Checking which subgroups commute

[Stefanos Dalamaidhs]

Dear Forum,

I would like to write a short code to do the following task:for any two
subgroups of a group G, check whether their product is a subgroup of G and
count their number. A failed attempt was:

G:=AlternatingGroup(4);
Alt( [ 1 .. 4 ] )

L:=LatticeSubgroups(G);

count:=0;

for H in L do;
for K in L do;
if IsSubgroup(G,HK) then count:=count+1;

 fi;
od;
od;
0
Error, no method found! For debugging hints type ?Recovery from
NoMethodFound
Error, no 1st choice method found for `Enumerator' on 1 arguments

I would be obliged for any help.

Thanks,
J.