Z{
  traversal-pp void f(float f) {
     // the wrappers below may refer to x,y and rv
     to X
    before {:> :r R,s,*,
	    B,
	    -> T,u,V,
	    => X,y,Z,
	    C,
	    :p W,
            -> :z W,*, T  } (@ System.out.println( p ); @)

    after  { -> :w W,q,:q R } (@ System.out.println( f ); @)
  }
}