interface ihello
{
  in bool hello();

  behaviour
  {
    on hello: reply(false);
    on hello: reply(true);
  }
}

interface iworld
{
  in void hello();
  out void cruel();
  out void world();

  behaviour
  {
    on hello: cruel;
    on hello: world;
  }
}

component hello_blocking_sync
{
  provides ihello h;
  requires iworld w;

  behaviour
  {
    blocking on h.hello(): w.hello();
    on w.cruel(): h.reply(false);
    on w.world(): h.reply(true);
  }
}