logo

Expression of type Lambda

from the theory of proveit.core_expr_types.tuples

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, b, d, i, k
from proveit.core_expr_types import a_1_to_i, c_1_to_k
from proveit.logic import And, Equals, Forall, InSet
from proveit.numbers import Natural
In [2]:
# build up the expression from sub-expressions
expr = Lambda([i, k], Conditional(Forall(instance_param_or_params = [a_1_to_i, b, c_1_to_k, d], instance_expr = Equals([a_1_to_i, b, c_1_to_k], [a_1_to_i, d, c_1_to_k]).with_wrapping_at(2), condition = Equals(b, d)), And(InSet(i, Natural), InSet(k, Natural))))
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(i, k\right) \mapsto \left\{\forall_{a_{1}, a_{2}, \ldots, a_{i}, b, c_{1}, c_{2}, \ldots, c_{k}, d~|~b = d}~\left(\begin{array}{c} \begin{array}{l} \left(a_{1}, a_{2}, \ldots, a_{i}, b,c_{1}, c_{2}, \ldots, c_{k}\right) =  \\ \left(a_{1}, a_{2}, \ldots, a_{i}, d,c_{1}, c_{2}, \ldots, c_{k}\right) \end{array} \end{array}\right) \textrm{ if } i \in \mathbb{N} ,  k \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
0Lambdaparameters: 1
body: 2
1ExprTuple30, 33
2Conditionalvalue: 3
condition: 4
3Operationoperator: 5
operand: 9
4Operationoperator: 7
operands: 8
5Literal
6ExprTuple9
7Literal
8ExprTuple10, 11
9Lambdaparameters: 12
body: 13
10Operationoperator: 15
operands: 14
11Operationoperator: 15
operands: 16
12ExprTuple26, 25, 28, 27
13Conditionalvalue: 17
condition: 18
14ExprTuple30, 19
15Literal
16ExprTuple33, 19
17Operationoperator: 21
operands: 20
18Operationoperator: 21
operands: 22
19Literal
20ExprTuple23, 24
21Literal
22ExprTuple25, 27
23ExprTuple26, 25, 28
24ExprTuple26, 27, 28
25Variable
26ExprRangelambda_map: 29
start_index: 32
end_index: 30
27Variable
28ExprRangelambda_map: 31
start_index: 32
end_index: 33
29Lambdaparameter: 39
body: 34
30Variable
31Lambdaparameter: 39
body: 35
32Literal
33Variable
34IndexedVarvariable: 36
index: 39
35IndexedVarvariable: 37
index: 39
36Variable
37Variable
38ExprTuple39
39Variable