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, a, b, c, d
from proveit.logic import And, Equals

# build up the expression from sub-expressions
expr = Lambda([a, b, c, d], Conditional(Equals(a, d), And(Equals(a, b), Equals(b, c), Equals(c, 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\{a = d \textrm{ if } a = b ,  b = c ,  c = 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	15, 16, 17, 18
2	Conditional	value: 3 condition: 4
3	Operation	operator: 13 operands: 5
4	Operation	operator: 6 operands: 7
5	ExprTuple	15, 18
6	Literal
7	ExprTuple	8, 9, 10
8	Operation	operator: 13 operands: 11
9	Operation	operator: 13 operands: 12
10	Operation	operator: 13 operands: 14
11	ExprTuple	15, 16
12	ExprTuple	16, 17
13	Literal
14	ExprTuple	17, 18
15	Variable
16	Variable
17	Variable
18	Variable