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Expression of type Lambda

from the theory of proveit.logic.booleans.quantification.existence

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, n
from proveit.core_expr_types import P__y_1_to_n, y_1_to_n
from proveit.logic import Forall, InSet
from proveit.logic.booleans.quantification import general_exists_Px
from proveit.numbers import NaturalPos
In [2]:
# build up the expression from sub-expressions
expr = Lambda(n, Conditional(Forall(instance_param_or_params = [P], instance_expr = Forall(instance_param_or_params = [y_1_to_n], instance_expr = general_exists_Px, condition = P__y_1_to_n)), InSet(n, NaturalPos)))
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())
n \mapsto \left\{\forall_{P}~\left[\forall_{y_{1}, y_{2}, \ldots, y_{n}~|~P\left(y_{1}, y_{2}, \ldots, y_{n}\right)}~\left[\exists_{x_{1}, x_{2}, \ldots, x_{n}}~P\left(x_{1}, x_{2}, \ldots, x_{n}\right)\right]\right] \textrm{ if } n \in \mathbb{N}^+\right..
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameter: 32
body: 2
1ExprTuple32
2Conditionalvalue: 3
condition: 4
3Operationoperator: 12
operand: 8
4Operationoperator: 6
operands: 7
5ExprTuple8
6Literal
7ExprTuple32, 9
8Lambdaparameter: 25
body: 11
9Literal
10ExprTuple25
11Operationoperator: 12
operand: 14
12Literal
13ExprTuple14
14Lambdaparameters: 20
body: 15
15Conditionalvalue: 16
condition: 17
16Operationoperator: 18
operand: 21
17Operationoperator: 25
operands: 20
18Literal
19ExprTuple21
20ExprTuple22
21Lambdaparameters: 26
body: 23
22ExprRangelambda_map: 24
start_index: 31
end_index: 32
23Operationoperator: 25
operands: 26
24Lambdaparameter: 36
body: 27
25Variable
26ExprTuple28
27IndexedVarvariable: 29
index: 36
28ExprRangelambda_map: 30
start_index: 31
end_index: 32
29Variable
30Lambdaparameter: 36
body: 33
31Literal
32Variable
33IndexedVarvariable: 34
index: 36
34Variable
35ExprTuple36
36Variable