interface ihello
{
  in void hello();

  out void world();

  behaviour
  {
    bool idle = true;
    [idle] on hello: idle=!idle;
    [!idle]{
      on hello: illegal;
      on inevitable: {idle=!idle; world;}
    }
  }
}

component hello_multiple_provides_requires
{
  provides ihello i1;
  provides ihello i2;

  requires ihello i3;

  behaviour
  {
    bool i1_idle = true;
    bool i2_idle = true;

    [i1_idle && i2_idle] on i1.hello(): {i1_idle = !i1_idle; i3.hello();}
    [i1_idle && i2_idle] on i2.hello(): {i2_idle = !i2_idle; i3.hello();}

    [i1_idle && !i2_idle] on i1.hello(): {i1_idle = !i1_idle;}
    [!i1_idle && i2_idle] on i2.hello(): {i2_idle = !i2_idle;}

    [!i1_idle] on i1.hello(): illegal;
    [!i2_idle] on i2.hello(): illegal;

    [!i1_idle && i2_idle] on i3.world(): {i1_idle = !i1_idle; i1.world();}
    [i1_idle && !i2_idle] on i3.world(): {i2_idle = !i2_idle; i2.world();}
    [!i1_idle && !i2_idle] on i3.world(): {i1_idle = !i1_idle; i1.world(); i3.hello();}

    [i1_idle && i2_idle] on i3.world(): illegal;
  }
}