// inside_cpow nested parent-to-child messages are verboten

//error: inside_cpow nested parent-to-child messages are verboten (here, message `Msg' in protocol `InsideCpowToChild')
//error: message `Msg' requires more powerful send semantics than its protocol `InsideCpowToChild' provides

[ChildProc=any]
protocol InsideCpowToChild {
child:
    [Nested=inside_cpow] sync Msg();
};