def _(expr):
# Implicitly assumes Mul has more than one arg
# Would be allargs(x, Q.prime(x) | Q.composite(x)) except 1 is composite
# More advanced prime assumptions will require inequalities, as 1 provides
# a corner case.
allargs_prime = allargs(x, Q.prime(x), expr)
return Implies(allargs_prime, ~Q.prime(expr))
def test_binary_symbols():
assert ITE(x < 1, y, z).binary_symbols == set((y, z))
for f in (Eq, Ne):
assert f(x, 1).binary_symbols == set()
assert f(x, True).binary_symbols == set([x])
assert f(x, False).binary_symbols == set([x])
assert S.true.binary_symbols == set()
assert S.false.binary_symbols == set()
assert x.binary_symbols == set([x])
assert And(x, Eq(y, False), Eq(z, 1)).binary_symbols == set([x, y])
assert Q.prime(x).binary_symbols == set()
assert Q.is_true(x < 1).binary_symbols == set()
assert Q.is_true(x).binary_symbols == set([x])
assert Q.is_true(Eq(x, True)).binary_symbols == set([x])
assert Q.prime(x).binary_symbols == set()
def test_binary_symbols():
assert ITE(x < 1, y, z).binary_symbols == set((y, z))
for f in (Eq, Ne):
assert f(x, 1).binary_symbols == set()
assert f(x, True).binary_symbols == set([x])
assert f(x, False).binary_symbols == set([x])
assert S.true.binary_symbols == set()
assert S.false.binary_symbols == set()
assert x.binary_symbols == set([x])
assert And(x, Eq(y, False), Eq(z, 1)).binary_symbols == set([x, y])
assert Q.prime(x).binary_symbols == set()
assert Q.is_true(x < 1).binary_symbols == set()
assert Q.is_true(x).binary_symbols == set([x])
assert Q.is_true(Eq(x, True)).binary_symbols == set([x])
assert Q.prime(x).binary_symbols == set()
def test_binary_symbols():
assert ITE(x < 1, y, z).binary_symbols == {y, z}
for f in (Eq, Ne):
assert f(x, 1).binary_symbols == set()
assert f(x, True).binary_symbols == {x}
assert f(x, False).binary_symbols == {x}
assert S.true.binary_symbols == set()
assert S.false.binary_symbols == set()
assert x.binary_symbols == {x}
assert And(x, Eq(y, False), Eq(z, 1)).binary_symbols == {x, y}
assert Q.prime(x).binary_symbols == set()
assert Q.lt(x, 1).binary_symbols == set()
assert Q.is_true(x).binary_symbols == {x}
assert Q.eq(x, True).binary_symbols == {x}
assert Q.prime(x).binary_symbols == set()
def test_prime():
assert satask(Q.prime(5)) is True
assert satask(Q.prime(6)) is False
assert satask(Q.prime(-5)) is False
assert satask(Q.prime(x*y), Q.integer(x) & Q.integer(y)) is None
assert satask(Q.prime(x*y), Q.prime(x) & Q.prime(y)) is False
def test_prime_composite():
assert satask(Q.prime(x), Q.composite(x)) is False
assert satask(Q.composite(x), Q.prime(x)) is False
assert satask(Q.composite(x), ~Q.prime(x)) is None
assert satask(Q.prime(x), ~Q.composite(x)) is None
# since 1 is neither prime nor composite the following should hold
assert satask(Q.prime(x), Q.integer(x) & Q.positive(x) & ~Q.composite(x)) is None
assert satask(Q.prime(2)) is True
assert satask(Q.prime(4)) is False
assert satask(Q.prime(1)) is False
assert satask(Q.composite(1)) is False
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