anchor.diff:      end;
   list_unification_3([], _) ->
       [false];
  -list_unification_3(List1=[H1|T1], List2=[H2|T2]) ->
  +list_unification_3(_List1=[H1|T1], List2=[H2|T2]) ->
       case is_meta_list(H1) of
           true ->
               T11= [T||T<-T1, not is_meta_list(T)],
  
positive.code:                              H1Sub = create_sub(H1, lists:sublist(List2, I)),
                               Res=list_unification_1(T1, lists:nthtail(I, List2)),
                               combine_unification_results(H1Sub, Res)
                           end||I<-lists:seq(1,Len2-Len1)],
                      lists:append(Res)
              end;
          false ->
  
negative.code:                                         is_meta_meta_list_variable(B);  
                                  _ -> false
                              end;
                          _ -> false
                      end;
                  _ ->
  