interface Intf {
  in void evt();
  behaviour {
    on evt: {}
  }
}

component Comp {
  provides Intf i;
  behaviour {
    on i.evt(): {}
  }
}

component System {
  provides Intf i1;
  
  system {
    Comp comp1;
    Comp comp2;
    i1 <=> comp1.i;
    i1 <=> comp2.i;
  }
}