Dear friends, I am writing a GAP code to check the following property: The join of any two permutable subgroup is a PERMUTABLE subgroup. I have a code that gives all permutable subgroups in a given group (PermutableSubgroups(g)). Here is my code:
IsPermJoinGroup:=function(g)local i,n,j,c; if IsAbelian(g)=truethen return true; fi; n:=PermutableSubgroups(g); if Size(n)=1 thenreturn true; fi; for i in[1..Size(n)] do for j in [i+1..n]do c:= ClosureGroup (n[i],n[j]); if not c in n then return false; fi; od; od; return true; end; When I checked if s4:= the symmetric group on 4 elements satisfies this property I get this message: IsPermJoinGroup(s4); Error, Range: <last> must be an integer (not a list (plain,hom)) in for j in [ i + 1 .. n ] do c := ClosureGroup( n[i], n[j] ); if not c in n then return false; fi; od; at *stdin*:1313 called from <function "IsPermJoinGroup">( <arguments> ) called from read-eval loop at *stdin*:1319 you can replace <last> via 'return <last>;' Any suggestion please. Thank you. _______________________________________________ Forum mailing list Forum@gap-system.org https://mail.gap-system.org/mailman/listinfo/forum
