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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
from proveit.core_expr_types import a_1_to_i, c_1_to_k
from proveit.logic import Equals
In [2]:
# build up the expression from sub-expressions
expr = Lambda([a_1_to_i, b, c_1_to_k, d], Conditional(Equals([a_1_to_i, b, c_1_to_k], [a_1_to_i, d, c_1_to_k]).with_wrapping_at(2), Equals(b, d)))
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(a_{1}, a_{2}, \ldots, a_{i}, b, c_{1}, c_{2}, \ldots, c_{k}, d\right) \mapsto \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} \textrm{ if } b = d\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
1ExprTuple11, 10, 13, 12
2Conditionalvalue: 3
condition: 4
3Operationoperator: 6
operands: 5
4Operationoperator: 6
operands: 7
5ExprTuple8, 9
6Literal
7ExprTuple10, 12
8ExprTuple11, 10, 13
9ExprTuple11, 12, 13
10Variable
11ExprRangelambda_map: 14
start_index: 17
end_index: 15
12Variable
13ExprRangelambda_map: 16
start_index: 17
end_index: 18
14Lambdaparameter: 24
body: 19
15Variable
16Lambdaparameter: 24
body: 20
17Literal
18Variable
19IndexedVarvariable: 21
index: 24
20IndexedVarvariable: 22
index: 24
21Variable
22Variable
23ExprTuple24
24Variable