anchor.diff:      case module_of(Instr) of
           {value, Mod} ->
               modules_of2(Instructions, [Mod|Acc]);
  +	skip ->
  +	    skip;
           false ->
               modules_of2(Instructions, Acc)
       end.
  
positive.code: modules_of([], Acc) ->
      lists:reverse(Acc);
  modules_of([{V,Instructions}|T], Acc) ->
      Mods = modules_of2(Instructions, []),
      modules_of(T, [{V, Mods}|Acc]).
   
  modules_of2([], Acc) ->
      lists:reverse(Acc);
  
negative.code: do_check_module_subset([_]) ->
      ok;
  do_check_module_subset([{_V1, Mods1}|T]) ->
      %% io:format("do_check_module_subset -> "
      %% 	      "~n   V1:    ~p"
      %% 	      "~n   Mods1: ~p"
      %% 	      "~n   T:     ~p"
      %% 	      "~n", [_V1, Mods1, T]),
      {V2, Mods2} = hd(T),
      %% Check that the modules in V1 is a subset of V2
      case do_check_module_subset2(Mods1, Mods2) of
  