interface ihello
{
  in void hello();
  in void hi();

  behaviour
  {
    bool b=false;
    on hello: b=!b;
    [b] on hi: b=!b;
    [!b] on hi: illegal;
  }
}

component hello_implicit_illegal
{
  provides ihello h;
  behaviour
  {
    bool b=false;
    on h.hello(): b=!b;
    [b] on h.hi (): b=!b;
  }
}