Common register_meas of type Qcircuit

from the theory of proveit.physics.quantum.circuits

import proveit
# Automation is not needed when only building an expression:
proveit.defaults.automation = False # This will speed things up.
proveit.defaults.inline_pngs = False # Makes files smaller.
%load_expr # Load the stored expression as 'stored_expr'
# import the special expression
from proveit.physics.quantum.circuits import register_meas

# check that the built expression is the same as the stored expression
assert register_meas == stored_expr
assert register_meas._style_id == stored_expr._style_id
print("Passed sanity check: register_meas matches stored_expr")

Passed sanity check: register_meas matches stored_expr

# Show the LaTeX representation of the expression for convenience if you need it.
print(stored_expr.latex())

\begin{array}{c} \Qcircuit@C=1em @R=.7em{
\multiqin{3}{\lvert \psi \rangle} & \meter & \multiqout{3}{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \meter & \ghostqout{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \measure{\begin{array}{c}:\\ \left(m - 3\right) \times \\:\end{array}} \qw & \ghostqout{\lvert n \rangle_{m}} \\
\ghostqin{\lvert \psi \rangle} & \meter & \ghostqout{\lvert n \rangle_{m}}
} \end{array}

stored_expr.style_options()

name	description	default	current value	related methods
spacing	change the spacing of a circuit using the format '@C=1em @R=.7em' where C is the column spacing and R is the row spacing	@C=1em @R=.7em	@C=1em @R=.7em

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Operation	operator: 1 operands: 2
1	Literal
2	ExprTuple	3, 4, 5
3	ExprTuple	6
4	ExprTuple	7
5	ExprTuple	8
6	ExprRange	lambda_map: 9 start_index: 34 end_index: 38
7	ExprRange	lambda_map: 10 start_index: 34 end_index: 38
8	ExprRange	lambda_map: 11 start_index: 34 end_index: 38
9	Lambda	parameter: 33 body: 12
10	Lambda	parameter: 33 body: 13
11	Lambda	parameter: 33 body: 15
12	Operation	operator: 19 operands: 16
13	Operation	operator: 17 operands: 18
14	ExprTuple	33
15	Operation	operator: 19 operands: 20
16	NamedExprs	element: 21 targets: 24
17	Literal
18	NamedExprs	basis: 22
19	Literal
20	NamedExprs	element: 23 targets: 24
21	Operation	operator: 25 operands: 26
22	Literal
23	Operation	operator: 27 operands: 28
24	Operation	operator: 29 operands: 30
25	Literal
26	NamedExprs	state: 31 part: 33
27	Literal
28	NamedExprs	state: 32 part: 33
29	Literal
30	ExprTuple	34, 38
31	Variable
32	Operation	operator: 35 operands: 36
33	Variable
34	Literal
35	Literal
36	ExprTuple	37, 38
37	Variable
38	Variable