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Expression of type Lambda

from the theory of proveit.core_expr_types.lambda_maps

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, f, g, i
from proveit.core_expr_types import a_1_to_i, b_1_to_i, c_1_to_i, f__a_1_to_i, f__b_1_to_i, g__a_1_to_i, g__c_1_to_i
from proveit.logic import Equals, Forall, Implies, InSet
from proveit.numbers import NaturalPos
In [2]:
# build up the expression from sub-expressions
expr = Lambda(i, Conditional(Forall(instance_param_or_params = [f, g], instance_expr = Implies(Forall(instance_param_or_params = [a_1_to_i], instance_expr = Equals(f__a_1_to_i, g__a_1_to_i)), Equals(Lambda([b_1_to_i], f__b_1_to_i), Lambda([c_1_to_i], g__c_1_to_i)).with_wrapping_at(2)).with_wrapping_at(2)), InSet(i, 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())
i \mapsto \left\{\forall_{f, g}~\left(\begin{array}{c} \begin{array}{l} \left[\forall_{a_{1}, a_{2}, \ldots, a_{i}}~\left(f\left(a_{1}, a_{2}, \ldots, a_{i}\right) = g\left(a_{1}, a_{2}, \ldots, a_{i}\right)\right)\right] \Rightarrow  \\ \left(\begin{array}{c} \begin{array}{l} \left[\left(b_{1}, b_{2}, \ldots, b_{i}\right) \mapsto f\left(b_{1}, b_{2}, \ldots, b_{i}\right)\right] =  \\ \left[\left(c_{1}, c_{2}, \ldots, c_{i}\right) \mapsto g\left(c_{1}, c_{2}, \ldots, c_{i}\right)\right] \end{array} \end{array}\right) \end{array} \end{array}\right) \textrm{ if } i \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: 43
body: 2
1ExprTuple43
2Conditionalvalue: 3
condition: 4
3Operationoperator: 16
operand: 8
4Operationoperator: 6
operands: 7
5ExprTuple8
6Literal
7ExprTuple43, 9
8Lambdaparameters: 10
body: 11
9Literal
10ExprTuple33, 34
11Operationoperator: 12
operands: 13
12Literal
13ExprTuple14, 15
14Operationoperator: 16
operand: 19
15Operationoperator: 25
operands: 18
16Literal
17ExprTuple19
18ExprTuple20, 21
19Lambdaparameters: 35
body: 22
20Lambdaparameters: 27
body: 23
21Lambdaparameters: 28
body: 24
22Operationoperator: 25
operands: 26
23Operationoperator: 33
operands: 27
24Operationoperator: 34
operands: 28
25Literal
26ExprTuple29, 30
27ExprTuple31
28ExprTuple32
29Operationoperator: 33
operands: 35
30Operationoperator: 34
operands: 35
31ExprRangelambda_map: 36
start_index: 42
end_index: 43
32ExprRangelambda_map: 37
start_index: 42
end_index: 43
33Variable
34Variable
35ExprTuple38
36Lambdaparameter: 49
body: 39
37Lambdaparameter: 49
body: 40
38ExprRangelambda_map: 41
start_index: 42
end_index: 43
39IndexedVarvariable: 44
index: 49
40IndexedVarvariable: 45
index: 49
41Lambdaparameter: 49
body: 46
42Literal
43Variable
44Variable
45Variable
46IndexedVarvariable: 47
index: 49
47Variable
48ExprTuple49
49Variable