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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 Lambda, Q, Qx, S, x
from proveit.logic import And, Forall, InSet
from proveit.logic.sets import basic_comprehension_y
In [2]:
# build up the expression from sub-expressions
expr = Lambda([S, Q], Forall(instance_param_or_params = [x], instance_expr = And(InSet(x, S), Qx), domain = basic_comprehension_y))
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(S, Q\right) \mapsto \left[\forall_{x \in \left\{y~|~Q\left(y\right)\right\}_{y \in S}}~\left(\left(x \in S\right) \land Q\left(x\right)\right)\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, 28
2Operationoperator: 3
operand: 5
3Literal
4ExprTuple5
5Lambdaparameter: 18
body: 6
6Conditionalvalue: 7
condition: 8
7Operationoperator: 22
operands: 9
8Operationoperator: 26
operands: 10
9ExprTuple11, 12
10ExprTuple18, 13
11Operationoperator: 26
operands: 14
12Operationoperator: 28
operand: 18
13Operationoperator: 16
operand: 19
14ExprTuple18, 30
15ExprTuple18
16Literal
17ExprTuple19
18Variable
19Lambdaparameter: 31
body: 20
20Conditionalvalue: 31
condition: 21
21Operationoperator: 22
operands: 23
22Literal
23ExprTuple24, 25
24Operationoperator: 26
operands: 27
25Operationoperator: 28
operand: 31
26Literal
27ExprTuple31, 30
28Variable
29ExprTuple31
30Variable
31Variable