Expression of type Lambda

from the theory of proveit.numbers.numerals.decimals

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 Lambda, n
from proveit.logic import And, Equals, InSet
from proveit.numbers import Digits, LessEq, Natural, nine

# build up the expression from sub-expressions
expr = Lambda(n, Equals(InSet(n, Digits), And(InSet(n, Natural), LessEq(n, nine))))

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())

n \mapsto \left(\left(n \in \mathbb{N}^{\leq 9}\right) = \left(\left(n \in \mathbb{N}\right) \land \left(n \leq 9\right)\right)\right)

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

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