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Expression of type Lambda

from the theory of proveit.logic.sets.comprehension

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 IndexedVar, Lambda, S, Variable, x
from proveit.logic import InSet
In [2]:
# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
expr = Lambda(sub_expr1, InSet(IndexedVar(x, sub_expr1), IndexedVar(S, sub_expr1)))
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())
{_{-}a} \mapsto \left(x_{{_{-}a}} \in S_{{_{-}a}}\right)
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameter: 9
body: 1
1Operationoperator: 2
operands: 3
2Literal
3ExprTuple4, 5
4IndexedVarvariable: 6
index: 9
5IndexedVarvariable: 7
index: 9
6Variable
7Variable
8ExprTuple9
9Variable