First recursive function I've written in years.

recurse:=function(G,B,i,g,f)
  local j;
  if Size(g) = (i-1) then
    if Size(g) = Size(B) then
      return f(g);
    else
      for j in Combinations(G,B[i]-1) do
        return recurse(G,B,i+1,Concatenation(g,[j]),f);
      od;
    fi;
  else return;
  fi;
end;


global_array:=[];
fun:=function(G,B,g)
  local gset,glist,difflist,gcopy,x,L,i,j,pos,idealdifflist;
#TODO Implement FindL, code's written, just wrap it up
  L:=2;#FindL(G,B);
  gcopy:=StructuralCopy(g);
  gset:=Flat(gcopy);
  glist:=List(G);
  difflist:=ConstantArray(0,Size(G));
  idealdifflist:=ConstantArray(L,Size(G));
  idealdifflist[Position(glist,One(G))]:=0;
  # if Id is not any one of the diffs;
  if Positions(gset,One(G))<>[] then
    return;
  else
    for i in [1..Size(gcopy)] do
      Add(gcopy[i],One(G));
    od;
#generate difflist
    for i in [1..Size(gcopy)] do
      for j in Tuples(gcopy[i],2) do
        pos:=Position(glist,j[1]*j[2]^-1);
        difflist[pos]:=difflist[pos]+1;
      od;
    od;
  fi;
#verify difflist
  if difflist = idealdifflist then
    Add(global_array,g);
  fi;
end;