interface I {
  in void e();
  in void a();
  out void ec();
  out void ac();

  behaviour {
    enum State { idle, busy, aborting };
    State s = State.idle;
    [s.idle] {
      on e: s = State.busy;
      on a: s = State.aborting;
    }
    [s.busy] {
      on e: illegal;
      on a: s = State.aborting;
      on inevitable: { ec; s = State.idle;}
    }
    [s.aborting] {
      on e: illegal;
      on a: illegal;
      on inevitable: { ac; s = State.idle;}
    }
  }
}

interface II {
  in void e();
  in void a();
  out void ec();
  out void ac();

  behaviour {
    enum State { idle };
    State s = State.idle;
    [s.idle] {
      on e: ec;
      on a: ac;
    }
  }
}

component asyncsync {
  provides I p;
  requires external II r;

  behaviour {
    enum State { idle, busy, aborting };
    State s = State.idle;
    [s.idle] {
      on p.e(): { r.e(); s = State.busy; }
      on p.a(): { r.a(); s = State.aborting;}
      on r.ec: illegal;
      on r.ac: illegal;
    }
    [s.busy] {
      on p.e: illegal;
      on p.a(): { r.a(); s = State.aborting;}
      on r.ec(): { p.ec(); s = State.idle;}
      on r.ac(): illegal;
    }
    [s.aborting] {
      on p.e: illegal;
      on p.a: illegal;
      on r.ec(): {}
      on r.ac(): { p.ac(); s = State.idle;}
    }
  }
}