// doubly - controlled Rz circuit with angle
// decompose in terms of V = sqrt(U)

scaff_module ccRz (
	qbit ctrl0,
	qbit ctrl1,
	qbit target,
	const double angle
) {
  cRz (ctrl1, target, angle/2);
  CNOT (ctrl0, ctrl1);
  cRz (ctrl1, target, -angle/2);
	CNOT (ctrl0, ctrl1);
  cRz (ctrl0, target, angle/2);
}