def test_re():
assert refine(re(x), Q.real(x)) == x
assert refine(re(x), Q.imaginary(x)) is S.Zero
assert refine(re(x+y), Q.real(x) & Q.real(y)) == x + y
assert refine(re(x+y), Q.real(x) & Q.imaginary(y)) == x
assert refine(re(x*y), Q.real(x) & Q.real(y)) == x * y
assert refine(re(x*y), Q.real(x) & Q.imaginary(y)) == 0
assert refine(re(x*y*z), Q.real(x) & Q.real(y) & Q.real(z)) == x * y * z
def test_imaginary():
assert satask(Q.imaginary(2*I)) is True
assert satask(Q.imaginary(x*y), Q.imaginary(x)) is None
assert satask(Q.imaginary(x*y), Q.imaginary(x) & Q.real(y)) is True
assert satask(Q.imaginary(x), Q.real(x)) is False
assert satask(Q.imaginary(1)) is False
assert satask(Q.imaginary(x*y), Q.real(x) & Q.real(y)) is False
assert satask(Q.imaginary(x + y), Q.real(x) & Q.real(y)) is False
def test_real():
assert satask(Q.real(x*y), Q.real(x) & Q.real(y)) is True
assert satask(Q.real(x + y), Q.real(x) & Q.real(y)) is True
assert satask(Q.real(x*y*z), Q.real(x) & Q.real(y) & Q.real(z)) is True
assert satask(Q.real(x*y*z), Q.real(x) & Q.real(y)) is None
assert satask(Q.real(x*y*z), Q.real(x) & Q.real(y) & Q.imaginary(z)) is False
assert satask(Q.real(x + y + z), Q.real(x) & Q.real(y) & Q.real(z)) is True
assert satask(Q.real(x + y + z), Q.real(x) & Q.real(y)) is None
def test_im():
assert refine(im(x), Q.imaginary(x)) == -I*x
assert refine(im(x), Q.real(x)) is S.Zero
assert refine(im(x+y), Q.imaginary(x) & Q.imaginary(y)) == -I*x - I*y
assert refine(im(x+y), Q.real(x) & Q.imaginary(y)) == -I*y
assert refine(im(x*y), Q.imaginary(x) & Q.real(y)) == -I*x*y
assert refine(im(x*y), Q.imaginary(x) & Q.imaginary(y)) == 0
assert refine(im(1/x), Q.imaginary(x)) == -I/x
assert refine(im(x*y*z), Q.imaginary(x) & Q.imaginary(y)
& Q.imaginary(z)) == -I*x*y*z
def _(expr):
# General Case: Odd number of imaginary args implies mul is imaginary(To be implemented)
allargs_imag_or_real = allargs(x, Q.imaginary(x) | Q.real(x), expr)
onearg_imaginary = exactlyonearg(x, Q.imaginary(x), expr)
return Implies(allargs_imag_or_real,
Implies(onearg_imaginary, Q.imaginary(expr)))
def get_known_facts(x=None):
"""
Facts between unary predicates.
Parameters
==========
x : Symbol, optional
Placeholder symbol for unary facts. Default is ``Symbol('x')``.
Returns
=======
fact : Known facts in conjugated normal form.
"""
if x is None:
x = Symbol('x')
fact = And(
# primitive predicates for extended real exclude each other.
Exclusive(Q.negative_infinite(x), Q.negative(x), Q.zero(x),
Q.positive(x), Q.positive_infinite(x)),
# build complex plane
Exclusive(Q.real(x), Q.imaginary(x)),
Implies(Q.real(x) | Q.imaginary(x), Q.complex(x)),
# other subsets of complex
Exclusive(Q.transcendental(x), Q.algebraic(x)),
Equivalent(Q.real(x),
Q.rational(x) | Q.irrational(x)),
Exclusive(Q.irrational(x), Q.rational(x)),
Implies(Q.rational(x), Q.algebraic(x)),
# integers
Exclusive(Q.even(x), Q.odd(x)),
Implies(Q.integer(x), Q.rational(x)),
Implies(Q.zero(x), Q.even(x)),
Exclusive(Q.composite(x), Q.prime(x)),
Implies(Q.composite(x) | Q.prime(x),
Q.integer(x) & Q.positive(x)),
Implies(Q.even(x) & Q.positive(x) & ~Q.prime(x), Q.composite(x)),
# hermitian and antihermitian
Implies(Q.real(x), Q.hermitian(x)),
Implies(Q.imaginary(x), Q.antihermitian(x)),
Implies(Q.zero(x),
Q.hermitian(x) | Q.antihermitian(x)),
# define finity and infinity, and build extended real line
Exclusive(Q.infinite(x), Q.finite(x)),
Implies(Q.complex(x), Q.finite(x)),
Implies(
Q.negative_infinite(x) | Q.positive_infinite(x), Q.infinite(x)),
# commutativity
Implies(Q.finite(x) | Q.infinite(x), Q.commutative(x)),
# matrices
Implies(Q.orthogonal(x), Q.positive_definite(x)),
Implies(Q.orthogonal(x), Q.unitary(x)),
Implies(Q.unitary(x) & Q.real_elements(x), Q.orthogonal(x)),
Implies(Q.unitary(x), Q.normal(x)),
Implies(Q.unitary(x), Q.invertible(x)),
Implies(Q.normal(x), Q.square(x)),
Implies(Q.diagonal(x), Q.normal(x)),
Implies(Q.positive_definite(x), Q.invertible(x)),
Implies(Q.diagonal(x), Q.upper_triangular(x)),
Implies(Q.diagonal(x), Q.lower_triangular(x)),
Implies(Q.lower_triangular(x), Q.triangular(x)),
Implies(Q.upper_triangular(x), Q.triangular(x)),
Implies(Q.triangular(x),
Q.upper_triangular(x) | Q.lower_triangular(x)),
Implies(Q.upper_triangular(x) & Q.lower_triangular(x), Q.diagonal(x)),
Implies(Q.diagonal(x), Q.symmetric(x)),
Implies(Q.unit_triangular(x), Q.triangular(x)),
Implies(Q.invertible(x), Q.fullrank(x)),
Implies(Q.invertible(x), Q.square(x)),
Implies(Q.symmetric(x), Q.square(x)),
Implies(Q.fullrank(x) & Q.square(x), Q.invertible(x)),
Equivalent(Q.invertible(x), ~Q.singular(x)),
Implies(Q.integer_elements(x), Q.real_elements(x)),
Implies(Q.real_elements(x), Q.complex_elements(x)),
)
return fact