anchor.diff:                               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)],
  +                         end||I<-lists:seq(0,Len2-Len1)],
                       lists:append(Res)
               end;
           false ->
  
positive.code: list_unification_1(Exp1, Exp2)->
      LEs1 = [E||E<-Exp1,is_list(E)],
      LEs2 = [E||E<-Exp2,is_list(E)],
      case LEs1==[] andalso LEs2==[] of 
          false ->
              case  has_meta_list(Exp1) of
                  false ->
  
negative.code:     end;
  list_unification_3([], _) ->
      [false];
  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)],
  