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Expression of type Conditional

from the theory of proveit.physics.quantum.algebra

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, ExprRange, IndexedVar, Variable, i, lambda_, m, n
from proveit.core_expr_types import a_i, b_i, lambda_i
from proveit.linear_algebra import ScalarMult, VecSum
from proveit.logic import And, Equals, InSet
from proveit.numbers import Interval, Min, RealNonNeg, one
from proveit.physics.quantum import Ket, Qmult, var_ket_psi
In [2]:
# build up the expression from sub-expressions
sub_expr1 = Variable("_a", latex_format = r"{_{-}a}")
sub_expr2 = Min(m, n)
expr = Conditional(Equals(var_ket_psi, VecSum(index_or_indices = [i], summand = ScalarMult(lambda_i, Qmult(Ket(a_i), Ket(b_i))), domain = Interval(one, sub_expr2))), And(ExprRange(sub_expr1, InSet(IndexedVar(lambda_, sub_expr1), RealNonNeg), one, sub_expr2)))
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\{\lvert \psi \rangle = \left(\sum_{i=1}^{{\rm Min}\left(m, n\right)} \left(\lambda_{i} \cdot \left(\lvert a_{i} \rangle \thinspace \lvert b_{i} \rangle\right)\right)\right) \textrm{ if } \left(\lambda_{1} \in \mathbb{R}^{\ge 0}\right) \land  \left(\lambda_{2} \in \mathbb{R}^{\ge 0}\right) \land  \ldots \land  \left(\lambda_{{\rm Min}\left(m, n\right)} \in \mathbb{R}^{\ge 0}\right)\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: 5
operands: 6
3Literal
4ExprTuple7, 8
5Literal
6ExprTuple9
7Variable
8Operationoperator: 10
operand: 13
9ExprRangelambda_map: 12
start_index: 37
end_index: 38
10Literal
11ExprTuple13
12Lambdaparameter: 29
body: 14
13Lambdaparameter: 51
body: 15
14Operationoperator: 23
operands: 16
15Conditionalvalue: 17
condition: 18
16ExprTuple19, 20
17Operationoperator: 21
operands: 22
18Operationoperator: 23
operands: 24
19IndexedVarvariable: 30
index: 29
20Literal
21Literal
22ExprTuple26, 27
23Literal
24ExprTuple51, 28
25ExprTuple29
26IndexedVarvariable: 30
index: 51
27Operationoperator: 31
operands: 32
28Operationoperator: 33
operands: 34
29Variable
30Variable
31Literal
32ExprTuple35, 36
33Literal
34ExprTuple37, 38
35Operationoperator: 40
operand: 44
36Operationoperator: 40
operand: 45
37Literal
38Operationoperator: 42
operands: 43
39ExprTuple44
40Literal
41ExprTuple45
42Literal
43ExprTuple46, 47
44IndexedVarvariable: 48
index: 51
45IndexedVarvariable: 49
index: 51
46Variable
47Variable
48Variable
49Variable
50ExprTuple51
51Variable