logo

Expression of type Lambda

from the theory of proveit.logic.booleans.quantification.existence

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, P, Q
from proveit.logic import Implies
from proveit.logic.booleans.quantification import general_forall_Px_if_Qx, general_notexists_notPy_st_Qy
In [2]:
# build up the expression from sub-expressions
expr = Lambda([P, Q], Implies(general_forall_Px_if_Qx, general_notexists_notPy_st_Qy).with_wrapping_at(2))
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(P, Q\right) \mapsto \left(\begin{array}{c} \begin{array}{l} \left[\forall_{x_{1}, x_{2}, \ldots, x_{n}~|~Q\left(x_{1}, x_{2}, \ldots, x_{n}\right)}~P\left(x_{1}, x_{2}, \ldots, x_{n}\right)\right] \Rightarrow  \\ \left[\nexists_{y_{1}, y_{2}, \ldots, y_{n}~|~Q\left(y_{1}, y_{2}, \ldots, y_{n}\right)}~(\lnot P\left(y_{1}, y_{2}, \ldots, y_{n}\right))\right] \end{array} \end{array}\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
1ExprTuple26, 22
2Operationoperator: 3
operands: 4
3Literal
4ExprTuple5, 6
5Operationoperator: 7
operand: 11
6Operationoperator: 9
operand: 12
7Literal
8ExprTuple11
9Literal
10ExprTuple12
11Lambdaparameters: 19
body: 13
12Lambdaparameters: 27
body: 14
13Conditionalvalue: 15
condition: 16
14Conditionalvalue: 17
condition: 18
15Operationoperator: 26
operands: 19
16Operationoperator: 22
operands: 19
17Operationoperator: 20
operand: 24
18Operationoperator: 22
operands: 27
19ExprTuple23
20Literal
21ExprTuple24
22Variable
23ExprRangelambda_map: 25
start_index: 32
end_index: 33
24Operationoperator: 26
operands: 27
25Lambdaparameter: 37
body: 28
26Variable
27ExprTuple29
28IndexedVarvariable: 30
index: 37
29ExprRangelambda_map: 31
start_index: 32
end_index: 33
30Variable
31Lambdaparameter: 37
body: 34
32Literal
33Variable
34IndexedVarvariable: 35
index: 37
35Variable
36ExprTuple37
37Variable