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, a, k
from proveit.logic import InSet
from proveit.numbers import Interval, nine, one, subtract, two

# build up the expression from sub-expressions
expr = Conditional(subtract(k, two), InSet(k, Interval(a, subtract(nine, one))))

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\{k - 2 \textrm{ if } k \in \{a~\ldotp \ldotp~9 - 1\}\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: 15 operands: 3
2	Operation	operator: 4 operands: 5
3	ExprTuple	7, 6
4	Literal
5	ExprTuple	7, 8
6	Operation	operator: 19 operand: 12
7	Variable
8	Operation	operator: 10 operands: 11
9	ExprTuple	12
10	Literal
11	ExprTuple	13, 14
12	Literal
13	Variable
14	Operation	operator: 15 operands: 16
15	Literal
16	ExprTuple	17, 18
17	Literal
18	Operation	operator: 19 operand: 21
19	Literal
20	ExprTuple	21
21	Literal