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(Or(A, B), And(InSet(A, Boolean), InSet(B, Boolean), Not(And(Not(A), 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 \lor B \textrm{ if } A \in \mathbb{B} ,  B \in \mathbb{B} ,  \lnot \left((\lnot A) \land (\lnot B)\right)\right..

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameters: 5 body: 1
1	Conditional	value: 2 condition: 3
2	Operation	operator: 4 operands: 5
3	Operation	operator: 16 operands: 6
4	Literal
5	ExprTuple	23, 24
6	ExprTuple	7, 8, 9
7	Operation	operator: 11 operands: 10
8	Operation	operator: 11 operands: 12
9	Operation	operator: 21 operand: 15
10	ExprTuple	23, 14
11	Literal
12	ExprTuple	24, 14
13	ExprTuple	15
14	Literal
15	Operation	operator: 16 operands: 17
16	Literal
17	ExprTuple	18, 19
18	Operation	operator: 21 operand: 23
19	Operation	operator: 21 operand: 24
20	ExprTuple	23
21	Literal
22	ExprTuple	24
23	Variable
24	Variable