Update pennylane/registers.py

Co-authored-by: Utkarsh <utkarshazad98@gmail.com>

pennylane/registers.py

@@ -60,17 +60,23 @@ def registers(register_dict):
 
  .. code-block::
 
- reg = qml.registers({"aux": 1, "phi": 5, "psi": 5})
+ dev = qml.device("default.qubit")
+ reg = registers({"aux": 1, "phi": 5, "psi": 5})
 
+ @qml.qnode(dev)
  def circuit():
- qml.Hadamard(reg["aux"])
+ for state in ["phi", "psi"]:
+ qml.BasisState([1, 1, 0, 0, 0], reg[state])
 
+ qml.Hadamard(reg["aux"])
  for i in range(len(reg["phi"])):
- qml.CSWAP(reg["aux"] | reg["phi"][i] | reg["psi"][i])
-
+ qml.CSWAP(reg["aux"] + reg["phi"][i] + reg["psi"][i])
  qml.Hadamard(reg["aux"])
-
+ 
  return qml.expval(qml.Z(wires=reg["aux"]))
+
+>>> circuit()
+0.9999999999999996
  """
 
  def _registers(register_dict, _start_wire_index=0):