Expression of type Lambda

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, IndexedVar, Lambda, Variable, j, k, p

# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
expr = Lambda(sub_expr1, [IndexedVar(A, [p, j]), IndexedVar(B, [sub_expr1, j]), IndexedVar(C, [j, k]), IndexedVar(D, [k, sub_expr1])])

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())

{_{-}a} \mapsto \left(A_{p, j}, B_{{_{-}a}, j}, C_{j, k}, D_{k, {_{-}a}}\right)

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

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