startup classage expr18 {
   main(String[] args) {

    print("[ROUND 1]");
    create X();

    print("[ROUND 2]");
    create Y();

    print("[ROUND 3]");
    create XY(3);

    print("[ROUND 4]");
    create XY(true);

    print("[ROUND 5]");
    create YX(3);

    print("[ROUND 6]");
    create YX(true);

     // note: round 3 and round 5 print out the same result, which
     // shows the communicativeness of the compound process.
     // similarly, round 4 and round 6 print out the same result.

   }
}


classage XY = X + Y with A >> B {
    XY(int x) { :X(); :Y(); }
    XY(boolean b) {:Y(); :X(); }

}

classage YX = Y + X with B >> A {
    YX(int x) { :X(); :Y(); }
    YX(boolean b) {:Y(); :X(); }

}

classage X {

  X() {
    ::t();
  }

  mixer A {	 
    export void t0() {
      print("OK from export t0 of A");
    }
    import void t1()
    export void t1() {
      print("OK from export t1 of A");
    }
    export void t2() {
      print("OK from export t2 of A");
    }

    export void t3() {
      print("passive call for t0");
      t0();
      print("passive call for t1");
      t1();
    }

  }

  void t() {


    print("[1]");
    A::t0();





    print("[2]");
    A::t1();




    print("[3]");
    A::t2();




    print("[4]");
    A::t3();


    return;

  }



}


classage Y {

  Y() {
    ::t();
  }

  mixer B {
   import void t0()


   export void t0() {
      print("OK from export t0 of B");
      return;
   }


   export void t1() {
      print("OK from export t1 of B");
      return;
   }
  }

  void t() {

    print("[4]");
    B::t0();





    print("[5]");
    B::t1();


    return;

  }

}