# from the theory of proveit.physics.quantum.QPE¶

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.
# import Expression classes needed to build the expression
from proveit import e
from proveit.logic import Equals
from proveit.numbers import Add, Mult, Neg, one, subtract, two

In [2]:
# build up the expression from sub-expressions
expr = Equals(Add(Mult(two, e), Mult(Neg(one), e)), Mult(subtract(two, one), e))

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(2 \cdot e\right) + \left(\left(-1\right) \cdot e\right)\right) = \left(\left(2 - 1\right) \cdot e\right)

In [5]:
stored_expr.style_options()

namedescriptiondefaultcurrent valuerelated methods
operation'infix' or 'function' style formattinginfixinfix
wrap_positionsposition(s) at which wrapping is to occur; '2 n - 1' is after the nth operand, '2 n' is after the nth operation.()()('with_wrapping_at', 'with_wrap_before_operator', 'with_wrap_after_operator', 'without_wrapping', 'wrap_positions')
justificationif any wrap positions are set, justify to the 'left', 'center', or 'right'centercenter('with_justification',)
directionDirection of the relation (normal or reversed)normalnormal('with_direction_reversed', 'is_reversed')
In [6]:
# display the expression information
stored_expr.expr_info()

core typesub-expressionsexpression
0Operationoperator: 1
operands: 2
1Literal
2ExprTuple3, 4
3Operationoperator: 13
operands: 5
4Operationoperator: 11
operands: 6
5ExprTuple7, 8
6ExprTuple9, 15
7Operationoperator: 11
operands: 10
8Operationoperator: 11
operands: 12
9Operationoperator: 13
operands: 14
10ExprTuple16, 15
11Literal
12ExprTuple17, 15
13Literal
14ExprTuple16, 17
15Variable
16Literal
17Operationoperator: 18
operand: 20
18Literal
19ExprTuple20
20Literal