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, Or

# build up the expression from sub-expressions
expr = Lambda([A, B, C, D], Conditional(Or(C, D), And(InSet(A, Boolean), InSet(B, Boolean), InSet(C, Boolean), InSet(D, Boolean), Or(A, B), 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\{C \lor D \textrm{ if } A \in \mathbb{B} ,  B \in \mathbb{B} ,  C \in \mathbb{B} ,  D \in \mathbb{B} ,  A \lor B ,  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	26, 28, 27, 29
2	Conditional	value: 3 condition: 4
3	Operation	operator: 20 operands: 5
4	Operation	operator: 6 operands: 7
5	ExprTuple	27, 29
6	Literal
7	ExprTuple	8, 9, 10, 11, 12, 13, 14
8	Operation	operator: 18 operands: 15
9	Operation	operator: 18 operands: 16
10	Operation	operator: 18 operands: 17
11	Operation	operator: 18 operands: 19
12	Operation	operator: 20 operands: 21
13	Operation	operator: 23 operands: 22
14	Operation	operator: 23 operands: 24
15	ExprTuple	26, 25
16	ExprTuple	28, 25
17	ExprTuple	27, 25
18	Literal
19	ExprTuple	29, 25
20	Literal
21	ExprTuple	26, 28
22	ExprTuple	26, 27
23	Literal
24	ExprTuple	28, 29
25	Literal
26	Variable
27	Variable
28	Variable
29	Variable