anchor.diff:  %% Internal functions
   %% ====================================================================
   
  --spec find(term(),[term()],integer()) -> integer() | 'notFound'.
  -find(Elem,[Elem|_],Inc) ->
  +-spec find(term(), [term()], integer()) -> integer() | 'notFound'.
  +find(Elem, [Elem | _], Inc) ->
       Inc;
   
  -find(_,[],_) ->
  +find(_, [], _) ->
       notFound;
   
  -find(Elem,[_|T],Inc) ->
  -    find(Elem,T,Inc+1).
  -
  -
  --spec map_index(Elem::term(), Index::integer(), List::[term()], F::fun(), Acc::[term()]) -> [term()].
  -map_index(_,_,[],_,_) ->
  +find(Elem, [_ | T], Inc) ->
  +    find(Elem, T, Inc + 1).
  +
  +
  +-spec map_index(term(), integer(), [term()], fun(), [term()]) -> [term()].
  +map_index(_, _, [], _, _) ->
       erlang:error(wrongIndex);
   
  -map_index(Elem,1,[H|T],F,Acc) ->
  -    lists:reverse(Acc,[F(Elem,H)|T]);
  -
  -map_index(Elem,Index,[H|T],F,Acc) ->
  -    map_index(Elem,Index - 1,T,F,[H|Acc]).
  +map_index(Elem, 1, [H | T], F, Acc) ->
  +    lists:reverse(Acc, [F(Elem, H) | T]);
  +
  +map_index(Elem, Index, [H | T], F, Acc) ->
  +    map_index(Elem, Index - 1, T, F, [H | Acc]).
   
   
   -spec shortest_zip(list(), list(), list()) -> list().
  -shortest_zip([],_L2,Acc) ->
  +shortest_zip([], _L2, Acc) ->
       Acc;
   
  -shortest_zip(_L1,[],Acc) ->
  +shortest_zip(_L1, [], Acc) ->
       Acc;
   
  -shortest_zip([H1|T1],[H2|T2],Acc) ->
  -    shortest_zip(T1,T2,[{H1,H2}|Acc]).
  +shortest_zip([H1 | T1], [H2 | T2], Acc) ->
  +    shortest_zip(T1, T2, [{H1, H2} | Acc]).
  
positive.code:      Milisec + (Time rem 1000)}.
  
  
  %% @doc Maps function F(Elem, A) -> A' to an element A of List with Index. Returns updated list
  -spec map_index(Elem::term(), Index::integer(), List::[term()], F::fun()) -> [term()].
  map_index(Elem,Index,List,F) ->
      map_index(Elem,Index,List,F,[]).
  
  
  -spec clear_inbox() -> ok.
  
negative.code:     [migration | Env:behaviours()].
  
  
  %% @doc Computes an average number of elements
  %% that are chosen with given probability
  -spec average_number(float(), [term()]) -> integer().
  average_number(Probability, List) ->
      N = Probability * length(List),
      if N == 0 -> 0;
  