# M operation

Performs a measurement of a single qubit in the Pauli $Z$ basis, such that the output result is given by the distribution \begin{align} \Pr(\texttt{Zero} | \ket{\psi}) = \braket{\psi | 0} \braket{0 | \psi}. \end{align}

`operation M (qubit : Qubit) : Result`

## Input

- qubit
- Qubit

Qubit to be measured.

## Output

Result

`Zero`

if the $+1$ eigenvalue is observed, and `One`

if
the $-1$ eigenvalue is observed.

## Remarks

Equivalent to:

```
Measure([PauliZ], [qubit]);
```