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, C, Conditional, D, Lambda
from proveit.logic import And, Boolean, Implies, InSet, Not, Or

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

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

stored_expr.style_options()

no style options

# display the expression information
stored_expr.expr_info()

	core type	sub-expressions	expression
0	Lambda	parameters: 1 body: 2
1	ExprTuple	32, 33, 37, 38
2	Conditional	value: 3 condition: 4
3	Operation	operator: 24 operands: 5
4	Operation	operator: 6 operands: 7
5	ExprTuple	8, 9
6	Literal
7	ExprTuple	10, 11, 12, 13, 14, 15, 16
8	Operation	operator: 35 operand: 32
9	Operation	operator: 35 operand: 33
10	Operation	operator: 22 operands: 19
11	Operation	operator: 22 operands: 20
12	Operation	operator: 22 operands: 21
13	Operation	operator: 22 operands: 23
14	Operation	operator: 24 operands: 25
15	Operation	operator: 27 operands: 26
16	Operation	operator: 27 operands: 28
17	ExprTuple	32
18	ExprTuple	33
19	ExprTuple	32, 29
20	ExprTuple	33, 29
21	ExprTuple	37, 29
22	Literal
23	ExprTuple	38, 29
24	Literal
25	ExprTuple	30, 31
26	ExprTuple	32, 37
27	Literal
28	ExprTuple	33, 38
29	Literal
30	Operation	operator: 35 operand: 37
31	Operation	operator: 35 operand: 38
32	Variable
33	Variable
34	ExprTuple	37
35	Literal
36	ExprTuple	38
37	Variable
38	Variable