anchor.diff:      case get(trace_stack) of
   	false -> true;
   	_ -> %  all | no_tail
  -	    lists:any(fun({_,{M,_,_,_}}) when M =:= Mod -> true;
  +	    lists:any(fun(#e{mfa={M,_,_}}) when M =:= Mod -> true;
   			 (_) -> false
  -		      end,
  -		      get(?STACK))
  -    end.
  +		      end, get(?STACK))
  +    end.
  
positive.code: %%     Debugged when it should raise an exception or evaluate a
  %%     function (since it might possible raise an exception)
  %%
  %% Stack = [Entry]
  %%   Entry = {Le, {MFA, Where, Bs}}
  %%     Le = int()         % current call level
  %%     MFA = {M,F,Args}   % called function (or fun)
  %%         | {Fun,Args}   %
  %%     Where = {M,Li}     % from where (module+line) function is called
  %%     Bs = bindings()    % current variable bindings
  %%
  %% How to push depends on the "Stack Trace" option (value saved in
  %% process dictionary item 'trace_stack').
  %%   all - everything is pushed
  
negative.code: stack_frame(down, SP) ->
      stack_frame(SP, down, lists:reverse(get(?STACK))).
  
  stack_frame(SP, up, [#e{level=Le,cm=Cm,line=Li,bindings=Bs}|_]) when Le < SP ->
      {Le,{Cm,Li},Bs};
  stack_frame(SP, down, [#e{level=Le,cm=Cm,line=Li,bindings=Bs}|_]) when Le > SP ->
      {Le,{Cm,Li},Bs};
  stack_frame(SP, Dir, [#e{level=SP}|Stack]) ->
      case Stack of
  	[#e{level=Le,cm=Cm,line=Li,bindings=Bs}|_] ->
  	    {Le,{Cm,Li},Bs};
  	[] when Dir =:= up ->
  	    top;
  	[] when Dir =:= down ->
  