|
#(C) Graham Ellis, 2005-2006
#####################################################################
InstallGlobalFunction(ResolutionAbelianPcpGroup,
function(arg)
local
ResolutionAbGroup;
#####################################################################
#####################################################################
ResolutionAbGroup:=function(G,n)
local
gens, C, head, tail,
R, hom,x,tmp,FreeElts,
PcpG,
gens1,hom1,OriginalAppend;
###The last command is a real cheat!!
PcpG:=Pcp(G,"snf");
gens:=List([1..Length(PcpG)],i->PcpG[i]);
if Length(gens)=1 then
if IsFinite(Group(gens)) then return ResolutionFiniteGroup(gens,n);
else
HAPconstant:=50; #CHANGED JUNE 2022
tmp:=ResolutionAbelianGroup_alt([0],n);
HAPconstant:=5;
FreeElts:=tmp!.elts;
tmp!.appendToElts:=function(x)
local a,i,j;
a:=gens[1]; ######################HERE
for i in [0..10000] do
j:=false;
if a^i=x then j:=i; break; fi;
if a^-i=x then j:=-i; break; fi;
od;
Add(FreeElts,FreeElts[2]^j);
Add(tmp!.elts,x);
end;
tmp!.elts:=List(tmp!.elts,x->MappedWord(x,GeneratorsOfGroup(tmp!.group),
gens));
tmp!.group:=G;
return tmp;
fi;
fi;
if Length(gens)=0 then return
ResolutionFiniteGroup([Identity(G)],n); fi;
head:=Subgroup(G,[gens[1]]);
tail:=Subgroup(G,
List([2..Length(gens)],i->gens[i]));
R:=ResolutionDirectProduct(ResolutionAbGroup(head,n),
ResolutionAbGroup(tail,n),"internal");
return R;
end;
#####################################################################
#####################################################################
if IsPcpGroup(arg[1]) and IsAbelian(arg[1]) and IsInt(arg[2]) then
return ResolutionAbGroup(arg[1],arg[2]); fi;
if (not IsPcpGroup(arg[1])) and IsAbelian(arg[1]) and IsInt(arg[2]) then
return ResolutionAbelianGroup_alt(arg[1],arg[2]); fi;
Print("The first argument must be an abelian Pcp group. The second argument must be a positive integer. \n");
return fail;
end);
[ Dauer der Verarbeitung: 0.37 Sekunden
(vorverarbeitet)
]
|
