anchor.diff:  t_is_none_or_unit(_) -> false.
   
   %%-----------------------------------------------------------------------------
  -%% Atoms and the derived type bool
  +%% Atoms and the derived type boolean
   %%
   
   -spec t_atom() -> erl_type().
  
positive.code: 
  module_builtin_opaques(Module) ->
    [O || O <- all_opaque_builtins(), t_opaque_module(O) =:= Module].
             
  %%-----------------------------------------------------------------------------
  %% Remote types
  %% These types are used for preprocessing they should never reach the analysis stage
  
  -spec t_remote(module(), atom(), [_]) -> erl_type().
  
  
negative.code:     error -> 
        case dict:find(Id2, Dict) of
  	error -> {T, dict:store(Id2, T, Dict)};
  	{ok, Type} -> t_unify(T, Type, Dict, Opaques)
        end;
      {ok, Type1} ->
        case dict:find(Id2, Dict) of
  