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Expression of type Lambda

from the theory of proveit.logic.sets.enumeration

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_m, c_1_to_n
from proveit.logic import Equals, Set
In [2]:
# build up the expression from sub-expressions
expr = Lambda([a_1_to_m, b, c_1_to_n, d], Conditional(Equals(Set(a_1_to_m, b, c_1_to_n), Set(a_1_to_m, d, c_1_to_n)).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_{m}, b, c_{1}, c_{2}, \ldots, c_{n}, d\right) \mapsto \left\{\begin{array}{c} \begin{array}{l} \left\{a_{1}, a_{2}, \ldots, a_{m}, b,c_{1}, c_{2}, \ldots, c_{n}\right\} =  \\ \left\{a_{1}, a_{2}, \ldots, a_{m}, d,c_{1}, c_{2}, \ldots, c_{n}\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
1ExprTuple14, 13, 16, 15
2Conditionalvalue: 3
condition: 4
3Operationoperator: 6
operands: 5
4Operationoperator: 6
operands: 7
5ExprTuple8, 9
6Literal
7ExprTuple13, 15
8Operationoperator: 11
operands: 10
9Operationoperator: 11
operands: 12
10ExprTuple14, 13, 16
11Literal
12ExprTuple14, 15, 16
13Variable
14ExprRangelambda_map: 17
start_index: 20
end_index: 18
15Variable
16ExprRangelambda_map: 19
start_index: 20
end_index: 21
17Lambdaparameter: 27
body: 22
18Variable
19Lambdaparameter: 27
body: 23
20Literal
21Variable
22IndexedVarvariable: 24
index: 27
23IndexedVarvariable: 25
index: 27
24Variable
25Variable
26ExprTuple27
27Variable