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, ExprRange, IndexedVar, Lambda, Variable, n
from proveit.numbers import one

# build up the expression from sub-expressions
sub_expr1 = Variable("_b", latex_format = r"{_{-}b}")
sub_expr2 = Variable("_a", latex_format = r"{_{-}a}")
sub_expr3 = [sub_expr1, sub_expr2]
expr = Lambda(sub_expr1, ExprRange(sub_expr2, [IndexedVar(A, sub_expr3), IndexedVar(B, sub_expr3)], one, n).with_explicit_parameterization())

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())

{_{-}b} \mapsto \left(A_{{_{-}b}, 1}, B_{{_{-}b}, 1}\right), \left(A_{{_{-}b}, 2}, B_{{_{-}b}, 2}\right), ..\left(A_{{_{-}b}, {_{-}a}}, B_{{_{-}b}, {_{-}a}}\right).., \left(A_{{_{-}b}, n}, B_{{_{-}b}, n}\right)

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

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