Expression of type Conditional

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, ExprRange, IndexedVar, Variable, a, c, l
from proveit.logic import InSet
from proveit.numbers import Add, Integer, Mult, one, zero

# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
expr = Conditional(Mult(ExprRange(sub_expr1, IndexedVar(a, sub_expr1), one, zero), Add(l, one), IndexedVar(c, one)), InSet(l, Integer))

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\{a_{1} \cdot  a_{2} \cdot  \ldots \cdot  a_{0} \cdot \left(l + 1\right) \cdot c_{1} \textrm{ if } l \in \mathbb{Z}\right..

stored_expr.style_options()

name	description	default	current value	related methods
condition_delimiter	'comma' or 'and'	comma	comma	('with_comma_delimiter', 'with_conjunction_delimiter')

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Conditional	value: 1 condition: 2
1	Operation	operator: 3 operands: 4
2	Operation	operator: 5 operands: 6
3	Literal
4	ExprTuple	7, 8, 9
5	Literal
6	ExprTuple	18, 10
7	ExprRange	lambda_map: 11 start_index: 19 end_index: 12
8	Operation	operator: 13 operands: 14
9	IndexedVar	variable: 15 index: 19
10	Literal
11	Lambda	parameter: 22 body: 17
12	Literal
13	Literal
14	ExprTuple	18, 19
15	Variable
16	ExprTuple	19
17	IndexedVar	variable: 20 index: 22
18	Variable
19	Literal
20	Variable
21	ExprTuple	22
22	Variable