anchor.diff:  %%
   %% @see get_all_values/2
   
  --spec append_values(Key, List) -> List when
  -      Key :: term(),
  -      List :: [term()].
  +-spec append_values(Key, ListIn) -> ListOut when
  +      Key :: term(),
  +      ListIn :: [term()],
  +      ListOut :: [term()].
   
   append_values(Key, [P | Ps]) ->
       if is_atom(P), P =:= Key ->
  
positive.code: %% @see substitute_negations/2
  %% @see normalize/2
  
  -spec substitute_aliases(Aliases, List) -> List when
        Aliases :: [{Key, Key}],
        Key :: term(),
        List::[term()].
  
  substitute_aliases(As, Props) ->
      [substitute_aliases_1(As, P) || P <- Props].
  
negative.code: %%
  %% @see property/2
  
  -spec property(PropertyIn) -> PropertyOut when
        PropertyIn :: property(),
        PropertyOut :: property().
  
  property({Key, true}) when is_atom(Key) ->
      Key;
  