Expression of type Lambda

from the theory of proveit.numbers.summation

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 Conditional, Function, Lambda, Q, f
from proveit.core_expr_types import b_1_to_j

# build up the expression from sub-expressions
sub_expr1 = [b_1_to_j]
expr = Lambda(sub_expr1, Conditional(Function(f, sub_expr1), Function(Q, 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())

\left(b_{1}, b_{2}, \ldots, b_{j}\right) \mapsto \left\{f\left(b_{1}, b_{2}, \ldots, b_{j}\right) \textrm{ if } Q\left(b_{1}, b_{2}, \ldots, b_{j}\right)\right..

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameters: 6 body: 1
1	Conditional	value: 2 condition: 3
2	Operation	operator: 4 operands: 6
3	Operation	operator: 5 operands: 6
4	Variable
5	Variable
6	ExprTuple	7
7	ExprRange	lambda_map: 8 start_index: 9 end_index: 10
8	Lambda	parameter: 14 body: 11
9	Literal
10	Variable
11	IndexedVar	variable: 12 index: 14
12	Variable
13	ExprTuple	14
14	Variable