Expression of type Lambda

from the theory of proveit.logic.sets.enumeration

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, n, x
from proveit.core_expr_types import y_1_to_n
from proveit.logic import Equals, Forall, InSet, Set
from proveit.logic.sets import x_equals_any_y
from proveit.numbers import Natural

# build up the expression from sub-expressions
expr = Lambda(n, Conditional(Forall(instance_param_or_params = [x, y_1_to_n], instance_expr = Equals(InSet(x, Set(y_1_to_n)), x_equals_any_y).with_wrapping_at(2)), InSet(n, Natural)))

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\{\forall_{x, y_{1}, y_{2}, \ldots, y_{n}}~\left(\begin{array}{c} \begin{array}{l} \left(x \in \left\{y_{1}, y_{2}, \ldots, y_{n}\right\}\right) =  \\ \left(\left(x = y_{1}\right) \lor  \left(x = y_{2}\right) \lor  \ldots \lor  \left(x = y_{n}\right)\right) \end{array} \end{array}\right) \textrm{ if } n \in \mathbb{N}\right..

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameter: 28 body: 2
1	ExprTuple	28
2	Conditional	value: 3 condition: 4
3	Operation	operator: 5 operand: 8
4	Operation	operator: 15 operands: 7
5	Literal
6	ExprTuple	8
7	ExprTuple	28, 9
8	Lambda	parameters: 10 body: 11
9	Literal
10	ExprTuple	31, 24
11	Operation	operator: 29 operands: 12
12	ExprTuple	13, 14
13	Operation	operator: 15 operands: 16
14	Operation	operator: 17 operands: 18
15	Literal
16	ExprTuple	31, 19
17	Literal
18	ExprTuple	20
19	Operation	operator: 21 operands: 22
20	ExprRange	lambda_map: 23 start_index: 27 end_index: 28
21	Literal
22	ExprTuple	24
23	Lambda	parameter: 35 body: 25
24	ExprRange	lambda_map: 26 start_index: 27 end_index: 28
25	Operation	operator: 29 operands: 30
26	Lambda	parameter: 35 body: 32
27	Literal
28	Variable
29	Literal
30	ExprTuple	31, 32
31	Variable
32	IndexedVar	variable: 33 index: 35
33	Variable
34	ExprTuple	35
35	Variable