Hi everyone, I am back with another question today.

is it possible to include a mid-circuit-measurement, which is not unitary, inside the `qml.ctrl()`

operation?

I show you the code here:

```
import pennylane as qml
import numpy as np
import matplotlib.pyplot as plt
qubits = list(range(3))
dev = qml.device("default.qubit", wires=len(qubits))
@qml.qnode(dev, interface="numpy")
def circuit_mid_measurement(weights: np.array) -> float:
"""
Circuit with the mid-measurement operation inside.
:param weights: (np.array) The weights to feed the circuit with;
:return: measurement (float) The measurement.
"""
qml.RX(weights[0], wires=qubits[0])
m_outcome = qml.measure(wires=qubits[1])
qml.cond(m_outcome, qml.U3)(weights[1], weights[2], weights[3], wires=qubits[2])
measurement = qml.expval(qml.PauliZ(wires=qubits[0]))
return measurement
trainable_weights = np.random.uniform(-1., 1., 4)
qml.draw_mpl(circuit_mid_measurement)(trainable_weights)
plt.show()
# This cell is done only for plotting the mid-circuit custom unitary I would like to add inside
# a larger quantum circuit.
def mid_circuit_measure(weights: np.array) -> None:
"""
Circuit with the mid-measurement operation inside.
:param weights: (np.array) The weights to feed the circuit with;
:return: None.
"""
qml.RX(weights[0], wires=qubits[0])
m_outcome = qml.measure(wires=qubits[1])
qml.cond(m_outcome, qml.U3)(weights[1], weights[2], weights[3], wires=qubits[2])
dev2 = qml.device("default.qubit", wires=len(qubits)+1)
@qml.qnode(device=dev2, interface="numpy")
def circuit_total(weights: np.array) -> float:
"""
Total circuit which applies a customized operation with a mid-circuit measurement inside.
:param weights: (np.array) The weights to feed the circuit with;
:return: measurement: (float) The measured value of the circuit.
"""
qml.ctrl(op=mid_circuit_measure, control=3, control_values=0)(
weights[:4]
)
measurement = qml.expval(qml.PauliZ(wires=qubits[0]))
return measurement
trainable_weights = np.random.uniform(-1., 1., 4)
qml.draw_mpl(circuit_total)(trainable_weights)
plt.show()
# In this cell I got the error:
ValueError: The object measure(wires=[1]) of type
<class 'pennylane.measurements.mid_measure.MidMeasureMP'> is not an Operator
or callable.
This error might occur if you apply ctrl to a list of operations instead of a
function or Operator.
```