anchor.diff:  %% escape(none, St) ->
   %%    St;
   escape([X], St) ->
  -    Vars = St#state.vars,
  +    Vars = St#intraprocedural_state.vars,
       X0 = dict:fetch(escape, Vars),
       X1 = join_single(X, X0),
       case equal_single(X0, X1) of
  
positive.code: 	'try' ->
  	    {Xs1, St1} = visit(try_arg(T), L, St),
  	    X = singleton(external),
  	    Vars = bind_vars(try_vars(T), [X], St1#state.vars),
  	    {Xs2, St2} = visit(try_body(T), L, St1#state{vars = Vars}),
  	    Evars = bind_vars(try_evars(T), [X, X, X], St2#state.vars),
  	    {Xs3, St3} = visit(try_handler(T), L, St2#state{vars = Evars}),
  	    {join(join(Xs1, Xs2), Xs3), St3};
  	'catch' ->
  	    {_, St1} = visit(catch_body(T), L, St),
  
negative.code: 			MessageType = message_type_from_args(A),
  			% io:format("message type from send: ~p~n", [MessageType]),
  
  			St#intraprocedural_state{sends = sets:add_element(MessageType, St#intraprocedural_state.sends)};
  		_ ->
  			St
  	end.
  