Expression of type Lambda

from the theory of proveit.logic.equality

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, P, Px, x
from proveit.logic import And, Not, PofFalse

# build up the expression from sub-expressions
expr = Lambda([P, x], Conditional(Px, And(PofFalse, Not(x))))

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(P, x\right) \mapsto \left\{P\left(x\right) \textrm{ if } P\left(\bot\right) ,  \lnot x\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	9, 14
2	Conditional	value: 3 condition: 4
3	Operation	operator: 9 operand: 14
4	Operation	operator: 5 operands: 6
5	Literal
6	ExprTuple	7, 8
7	Operation	operator: 9 operand: 13
8	Operation	operator: 11 operand: 14
9	Variable
10	ExprTuple	13
11	Literal
12	ExprTuple	14
13	Literal
14	Variable