def test_ComplexPlane_union():
# Polar form
c1 = ComplexPlane(Interval(0, 1)*Interval(0, 2*S.Pi), polar=True)
c2 = ComplexPlane(Interval(0, 1)*Interval(0, S.Pi), polar=True)
c3 = ComplexPlane(Interval(0, oo)*Interval(0, S.Pi), polar=True)
c4 = ComplexPlane(Interval(0, oo)*Interval(S.Pi, 2*S.Pi), polar=True)
p1 = Union(Interval(0, 1)*Interval(0, 2*S.Pi), Interval(0, 1)*Interval(0, S.Pi))
p2 = Union(Interval(0, oo)*Interval(0, S.Pi), Interval(0, oo)*Interval(S.Pi, 2*S.Pi))
assert c1.union(c2) == ComplexPlane(p1, polar=True)
assert c3.union(c4) == ComplexPlane(p2, polar=True)
# Rectangular form
c5 = ComplexPlane(Interval(2, 5)*Interval(6, 9))
c6 = ComplexPlane(Interval(4, 6)*Interval(10, 12))
c7 = ComplexPlane(Interval(0, 10)*Interval(-10, 0))
c8 = ComplexPlane(Interval(12, 16)*Interval(14, 20))
p3 = Union(Interval(2, 5)*Interval(6, 9), Interval(4, 6)*Interval(10, 12))
p4 = Union(Interval(0, 10)*Interval(-10, 0), Interval(12, 16)*Interval(14, 20))
assert c5.union(c6) == ComplexPlane(p3)
assert c7.union(c8) == ComplexPlane(p4)
assert c1.union(Interval(2, 4)) == Union(c1, Interval(2, 4))
assert c5.union(Interval(2, 4)) == Union(c5, Interval(2, 4))
