Expression of type VertExprArray

from the theory of proveit.core_expr_types.expr_arrays

import proveit
# Automation is not needed when 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 Expression classes needed to build the expression
from proveit import A, B, C, D, ExprRange, IndexedVar, Variable, VertExprArray, X, j, m
from proveit.numbers import one

# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
sub_expr2 = [sub_expr1, j]
expr = VertExprArray(ExprRange(sub_expr1, [IndexedVar(A, sub_expr2), IndexedVar(B, sub_expr2), IndexedVar(C, sub_expr2), IndexedVar(D, sub_expr2)], one, m).with_explicit_parameterization(), X, [D, C, B, A])

expr:

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

Passed sanity check: expr matches stored_expr

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

\begin{array}{cccccc} 
 A_{1, j} & A_{2, j} & \cdot \cdot A_{{_{-}a}, j} \cdot \cdot & A_{m, j} & \multirow{4}{*}{$\begin{array}{c} \uparrow \\ X \\ \downarrow \end{array}$} & D \\
B_{1, j} & B_{2, j} & \cdot \cdot B_{{_{-}a}, j} \cdot \cdot & B_{m, j} &  & C \\
C_{1, j} & C_{2, j} & \cdot \cdot C_{{_{-}a}, j} \cdot \cdot & C_{m, j} &  & B \\
D_{1, j} & D_{2, j} & \cdot \cdot D_{{_{-}a}, j} \cdot \cdot & D_{m, j} &  & A \\
\end{array}

stored_expr.style_options()

name	description	default	current value	related methods
justification	justify to the 'left', 'center', or 'right' in the array cells	center	center	with_justification

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	ExprTuple	1, 2, 3
1	ExprRange	lambda_map: 4 start_index: 5 end_index: 6
2	Variable
3	ExprTuple	16, 15, 14, 13
4	Lambda	parameter: 18 body: 8
5	Literal
6	Variable
7	ExprTuple	18
8	ExprTuple	9, 10, 11, 12
9	IndexedVar	variable: 13 indices: 17
10	IndexedVar	variable: 14 indices: 17
11	IndexedVar	variable: 15 indices: 17
12	IndexedVar	variable: 16 indices: 17
13	Variable
14	Variable
15	Variable
16	Variable
17	ExprTuple	18, 19
18	Variable
19	Variable