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: 
  -define(STACK, ?MODULE).
  
  -record(e,
  	{level,					%Level
  	 mfa,					%{Mod,Func,Args|Arity}|{Fun,Args}
  	 cm,					%Module called from
  	 line,					%Line called from
  	 bindings
  	 }).
  
  init() ->
      init([]).
  
  