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Expression of type Conditional

from the theory of proveit.numbers.absolute_value

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, x, y
from proveit.logic import And, Iff, InSet
from proveit.numbers import Abs, LessEq, Neg, Real, greater_eq, zero
In [2]:
# build up the expression from sub-expressions
expr = Conditional(Iff(LessEq(Abs(x), y), And(LessEq(Neg(y), x), LessEq(x, y))), And(InSet(x, Real), InSet(y, Real), greater_eq(y, zero)))
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\{\left(\left|x\right| \leq y\right) \Leftrightarrow \left(\left(\left(-y\right) \leq x\right) \land \left(x \leq y\right)\right) \textrm{ if } x \in \mathbb{R} ,  y \in \mathbb{R} ,  y \geq 0\right..
In [5]:
stored_expr.style_options()
namedescriptiondefaultcurrent valuerelated methods
condition_delimiter'comma' or 'and'commacomma('with_comma_delimiter', 'with_conjunction_delimiter')
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Conditionalvalue: 1
condition: 2
1Operationoperator: 3
operands: 4
2Operationoperator: 12
operands: 5
3Literal
4ExprTuple6, 7
5ExprTuple8, 9, 10
6Operationoperator: 26
operands: 11
7Operationoperator: 12
operands: 13
8Operationoperator: 15
operands: 14
9Operationoperator: 15
operands: 16
10Operationoperator: 26
operands: 17
11ExprTuple18, 32
12Literal
13ExprTuple19, 20
14ExprTuple29, 21
15Literal
16ExprTuple32, 21
17ExprTuple22, 32
18Operationoperator: 23
operand: 29
19Operationoperator: 26
operands: 25
20Operationoperator: 26
operands: 27
21Literal
22Literal
23Literal
24ExprTuple29
25ExprTuple28, 29
26Literal
27ExprTuple29, 32
28Operationoperator: 30
operand: 32
29Variable
30Literal
31ExprTuple32
32Variable