Expression of type Lambda

from the theory of proveit.logic.booleans.disjunction

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 A, B, Conditional, Lambda
from proveit.logic import And, Boolean, InSet, Not, Or

# build up the expression from sub-expressions
expr = Lambda([A, B], Conditional(A, And(InSet(A, Boolean), InSet(B, Boolean), Or(A, B), Not(B))))

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, B\right) \mapsto \left\{A \textrm{ if } A \in \mathbb{B} ,  B \in \mathbb{B} ,  A \lor B ,  \lnot B\right..

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

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