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, Lambda, c, d, fj, gj, j, x
from proveit.logic import InSet
from proveit.numbers import Interval, Mult

# build up the expression from sub-expressions
expr = Lambda(j, Conditional(Mult(Mult(x, gj), fj), InSet(j, Interval(c, d))))

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())

j \mapsto \left\{\left(x \cdot g\left(j\right)\right) \cdot f\left(j\right) \textrm{ if } j \in \{c~\ldotp \ldotp~d\}\right..

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameter: 21 body: 1
1	Conditional	value: 2 condition: 3
2	Operation	operator: 10 operands: 4
3	Operation	operator: 5 operands: 6
4	ExprTuple	7, 8
5	Literal
6	ExprTuple	21, 9
7	Operation	operator: 10 operands: 11
8	Operation	operator: 12 operand: 21
9	Operation	operator: 13 operands: 14
10	Literal
11	ExprTuple	15, 16
12	Variable
13	Literal
14	ExprTuple	17, 18
15	Variable
16	Operation	operator: 19 operand: 21
17	Variable
18	Variable
19	Variable
20	ExprTuple	21
21	Variable