Expression of type Lambda

from the theory of proveit.core_expr_types.tuples

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 ExprRange, Function, IndexedVar, Lambda, Variable, f, i, j

# build up the expression from sub-expressions
sub_expr1 = Variable("_b", latex_format = r"{_{-}b}")
sub_expr2 = Variable("_a", latex_format = r"{_{-}a}")
expr = Lambda(sub_expr1, ExprRange(sub_expr2, Function(IndexedVar(f, sub_expr1), [sub_expr2]), IndexedVar(i, sub_expr1), IndexedVar(j, 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())

{_{-}b} \mapsto f_{{_{-}b}}\left(i_{{_{-}b}}\right), f_{{_{-}b}}\left(i_{{_{-}b}} + 1\right), \ldots, f_{{_{-}b}}\left(j_{{_{-}b}}\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: 1
1	ExprRange	lambda_map: 2 start_index: 3 end_index: 4
2	Lambda	parameter: 12 body: 5
3	IndexedVar	variable: 6 index: 13
4	IndexedVar	variable: 7 index: 13
5	Operation	operator: 8 operand: 12
6	Variable
7	Variable
8	IndexedVar	variable: 10 index: 13
9	ExprTuple	12
10	Variable
11	ExprTuple	13
12	Variable
13	Variable