anchor.diff:  %% Whenever a function returns, the corresponding call frame is popped.
   
   push(MFA, Bs, #ieval{level=Le,module=Cm,line=Li,last_call=Lc}) ->
  -    Entry = {Le, {MFA, {Cm,Li}, Bs}},
  +    Entry = #e{level=Le,mfa=MFA,cm=Cm,line=Li,bindings=Bs},
       case get(trace_stack) of
   	false -> ignore;
   	no_tail when Lc ->
  
positive.code:     case get(trace_stack) of
  	false -> true;
  	_ -> %  all | no_tail
  	    lists:any(fun({_,{M,_,_,_}}) when M =:= Mod -> true;
  			 (_) -> false
  		      end,
  		      get(?STACK))
      end.
  
negative.code: 		all -> get(?STACK);
  		N -> lists:sublist(get(?STACK), N)
  	    end,
      [{Le,MFA} || #e{level=Le,mfa=MFA} <- Stack].
  
  %%--------------------------------------------------------------------
  %% in_use_p(Mod, Cm) -> boolean()
  