def test_contains():
assert 6 in ConditionSet(x, x > 5, Interval(1, 7))
assert (8 in ConditionSet(x, y > 5, Interval(1, 7))) is False
# `in` should give True or False; in this case there is not
# enough information for that result
raises(TypeError,
lambda: 6 in ConditionSet(x, y > 5, Interval(1, 7)))
# here, there is enough information but the comparison is
# not defined
raises(TypeError, lambda: 0 in ConditionSet(x, 1/x >= 0, S.Reals))
assert ConditionSet(x, y > 5, Interval(1, 7)
).contains(6) == (y > 5)
assert ConditionSet(x, y > 5, Interval(1, 7)
).contains(8) is S.false
assert ConditionSet(x, y > 5, Interval(1, 7)
).contains(w) == And(Contains(w, Interval(1, 7)), y > 5)
# This returns an unevaluated Contains object
# because 1/0 should not be defined for 1 and 0 in the context of
# reals.
assert ConditionSet(x, 1/x >= 0, S.Reals).contains(0) == \
Contains(0, ConditionSet(x, 1/x >= 0, S.Reals), evaluate=False)
c = ConditionSet((x, y), x + y > 1, S.Integers**2)
assert not c.contains(1)
assert c.contains((2, 1))
assert not c.contains((0, 1))
c = ConditionSet((w, (x, y)), w + x + y > 1, S.Integers*S.Integers**2)
assert not c.contains(1)
assert not c.contains((1, 2))
assert not c.contains(((1, 2), 3))
assert not c.contains(((1, 2), (3, 4)))
assert c.contains((1, (3, 4)))
def test_flatten():
"""Tests whether there is basic denesting functionality"""
inner = ConditionSet(x, sin(x) + x > 0)
outer = ConditionSet(x, Contains(x, inner), S.Reals)
assert outer == ConditionSet(x, sin(x) + x > 0, S.Reals)
inner = ConditionSet(y, sin(y) + y > 0)
outer = ConditionSet(x, Contains(y, inner), S.Reals)
assert outer != ConditionSet(x, sin(x) + x > 0, S.Reals)
inner = ConditionSet(x, sin(x) + x > 0).intersect(Interval(-1, 1))
outer = ConditionSet(x, Contains(x, inner), S.Reals)
assert outer == ConditionSet(x, sin(x) + x > 0, Interval(-1, 1))
def test_failing_contains():
# XXX This may have to return unevaluated Contains object
# because 1/0 should not be defined for 1 and 0 in the context of
# reals, but there is a nonsensical evaluation to ComplexInfinity
# and the comparison is giving an error.
assert ConditionSet(x, 1/x >= 0, S.Reals).contains(0) == \
Contains(0, ConditionSet(x, 1/x >= 0, S.Reals), evaluate=False)
def test_contains():
assert 6 in ConditionSet(x, x > 5, Interval(1, 7))
assert (8 in ConditionSet(x, y > 5, Interval(1, 7))) is False
# `in` should give True or False; in this case there is not
# enough information for that result
raises(TypeError, lambda: 6 in ConditionSet(x, y > 5, Interval(1, 7)))
assert ConditionSet(x, y > 5, Interval(1, 7)).contains(6) == (y > 5)
assert ConditionSet(x, y > 5, Interval(1, 7)).contains(8) is S.false
assert ConditionSet(x, y > 5, Interval(1, 7)).contains(w) == And(
Contains(w, Interval(1, 7)), y > 5)
def test_flatten():
"""Tests whether there is basic denesting functionality"""
inner = ConditionSet(x, sin(x) + x > 0)
outer = ConditionSet(x, Contains(x, inner), S.Reals)
assert outer == ConditionSet(x, sin(x) + x > 0, S.Reals)
inner = ConditionSet(y, sin(y) + y > 0)
outer = ConditionSet(x, Contains(y, inner), S.Reals)
assert outer != ConditionSet(x, sin(x) + x > 0, S.Reals)
inner = ConditionSet(x, sin(x) + x > 0).intersect(Interval(-1, 1))
outer = ConditionSet(x, Contains(x, inner), S.Reals)
assert outer == ConditionSet(x, sin(x) + x > 0, Interval(-1, 1))
def test_duplicate():
from sympy.core.function import BadSignatureError
# test coverage for line 95 in conditionset.py, check for duplicates in symbols
dup = symbols('a,a')
raises(BadSignatureError, lambda: ConditionSet(dup, x < 0))
def test_subs_CondSet():
s = FiniteSet(z, y)
c = ConditionSet(x, x < 2, s)
# you can only replace sym with a symbol that is not in
# the free symbols
assert c.subs(x, 1) == c
assert c.subs(x, y) == ConditionSet(y, y < 2, s)
# double subs needed to change dummy if the base set
# also contains the dummy
orig = ConditionSet(y, y < 2, s)
base = orig.subs(y, w)
and_dummy = base.subs(y, w)
assert base == ConditionSet(y, y < 2, {w, z})
assert and_dummy == ConditionSet(w, w < 2, {w, z})
assert c.subs(x, w) == ConditionSet(w, w < 2, s)
assert ConditionSet(x, x < y,
s).subs(y, w) == ConditionSet(x, x < w, s.subs(y, w))
# if the user uses assumptions that cause the condition
# to evaluate, that can't be helped from SymPy's end
n = Symbol('n', negative=True)
assert ConditionSet(n, 0 < n, S.Integers) is S.EmptySet
p = Symbol('p', positive=True)
assert ConditionSet(n, n < y, S.Integers).subs(n, x) == ConditionSet(
x, x < y, S.Integers)
nc = Symbol('nc', commutative=False)
raises(ValueError, lambda: ConditionSet(x, x < p, S.Integers).subs(x, nc))
raises(ValueError, lambda: ConditionSet(x, x < p, S.Integers).subs(x, n))
raises(ValueError, lambda: ConditionSet(x + 1, x < 1, S.Integers))
raises(ValueError, lambda: ConditionSet(x + 1, x < 1, s))
assert ConditionSet(n, n < x, Interval(0, oo)).subs(x,
p) == Interval(0, oo)
assert ConditionSet(n, n < x, Interval(-oo,
0)).subs(x, p) == Interval(-oo, 0)
assert ConditionSet(f(x),
f(x) < 1,
{w, z}).subs(f(x),
y) == ConditionSet(y, y < 1, {w, z})
# issue 17341
k = Symbol('k')
img1 = ImageSet(Lambda(k, 2 * k * pi + asin(y)), S.Integers)
img2 = ImageSet(Lambda(k, 2 * k * pi + asin(S.One / 3)), S.Integers)
assert ConditionSet(x, Contains(y, Interval(-1, 1)),
img1).subs(y, S.One / 3).dummy_eq(img2)
def test_subs_CondSet():
s = FiniteSet(z, y)
c = ConditionSet(x, x < 2, s)
assert c.subs(x, y) == c
assert c.subs(z, y) == ConditionSet(x, x < 2, FiniteSet(y))
assert c.xreplace({x: y}) == ConditionSet(y, y < 2, s)
assert ConditionSet(x, x < y, s
).subs(y, w) == ConditionSet(x, x < w, s.subs(y, w))
# if the user uses assumptions that cause the condition
# to evaluate, that can't be helped from SymPy's end
n = Symbol('n', negative=True)
assert ConditionSet(n, 0 < n, S.Integers) is S.EmptySet
p = Symbol('p', positive=True)
assert ConditionSet(n, n < y, S.Integers
).subs(n, x) == ConditionSet(n, n < y, S.Integers)
raises(ValueError, lambda: ConditionSet(
x + 1, x < 1, S.Integers))
assert ConditionSet(
p, n < x, Interval(-5, 5)).subs(x, p) == Interval(-5, 5), ConditionSet(
p, n < x, Interval(-5, 5)).subs(x, p)
assert ConditionSet(
n, n < x, Interval(-oo, 0)).subs(x, p
) == Interval(-oo, 0)
assert ConditionSet(f(x), f(x) < 1, {w, z}
).subs(f(x), y) == ConditionSet(f(x), f(x) < 1, {w, z})
# issue 17341
k = Symbol('k')
img1 = ImageSet(Lambda(k, 2*k*pi + asin(y)), S.Integers)
img2 = ImageSet(Lambda(k, 2*k*pi + asin(S.One/3)), S.Integers)
assert ConditionSet(x, Contains(
y, Interval(-1,1)), img1).subs(y, S.One/3).dummy_eq(img2)
assert (0, 1) in ConditionSet((x, y), x + y < 3, S.Integers**2)
raises(TypeError, lambda: ConditionSet(n, n < -10, Interval(0, 10)))
def test_as_relational():
assert ConditionSet((x, y), x > 1, S.Integers**2).as_relational((x, y)
) == (x > 1) & Contains((x, y), S.Integers**2)
assert ConditionSet(x, x > 1, S.Integers).as_relational(x
) == Contains(x, S.Integers) & (x > 1)
