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Expression of type Lambda

from the theory of proveit.logic.equality

In [1]:
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, PofTrue
In [2]:
# build up the expression from sub-expressions
expr = Lambda([P, x], Conditional(PofTrue, And(Px, x)))
expr:
In [3]:
# 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
In [4]:
# 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(\top\right) \textrm{ if } P\left(x\right) ,  x\right..
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameters: 1
body: 2
1ExprTuple10, 12
2Conditionalvalue: 3
condition: 4
3Operationoperator: 10
operand: 8
4Operationoperator: 6
operands: 7
5ExprTuple8
6Literal
7ExprTuple9, 12
8Literal
9Operationoperator: 10
operand: 12
10Variable
11ExprTuple12
12Variable