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Expression of type Lambda

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, Lambda, a, b
from proveit.logic import And, Equals, InSet, NotEquals
from proveit.numbers import Abs, Complex, frac, zero
In [2]:
# build up the expression from sub-expressions
expr = Lambda([a, b], Conditional(Equals(Abs(frac(a, b)), frac(Abs(a), Abs(b))), And(InSet(a, Complex), InSet(b, Complex), NotEquals(b, 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(a, b\right) \mapsto \left\{\left|\frac{a}{b}\right| = \frac{\left|a\right|}{\left|b\right|} \textrm{ if } a \in \mathbb{C} ,  b \in \mathbb{C} ,  b \neq 0\right..
In [5]:
stored_expr.style_options()
no style options
In [6]:
# display the expression information
stored_expr.expr_info()
 core typesub-expressionsexpression
0Lambdaparameters: 26
body: 1
1Conditionalvalue: 2
condition: 3
2Operationoperator: 4
operands: 5
3Operationoperator: 6
operands: 7
4Literal
5ExprTuple8, 9
6Literal
7ExprTuple10, 11, 12
8Operationoperator: 28
operand: 20
9Operationoperator: 25
operands: 14
10Operationoperator: 16
operands: 15
11Operationoperator: 16
operands: 17
12Operationoperator: 18
operands: 19
13ExprTuple20
14ExprTuple21, 22
15ExprTuple30, 23
16Literal
17ExprTuple31, 23
18Literal
19ExprTuple31, 24
20Operationoperator: 25
operands: 26
21Operationoperator: 28
operand: 30
22Operationoperator: 28
operand: 31
23Literal
24Literal
25Literal
26ExprTuple30, 31
27ExprTuple30
28Literal
29ExprTuple31
30Variable
31Variable