V s1 = Set([1, 2, 3, 4])
V s2 = Set([3, 4, 5, 6])
print(s1.union(s2))
print(s1.intersection(s2))
print(s1.difference(s2))
print(s1 < s1)
print(Set([3, 1]) < s1)
print(s1 <= s1)
print(Set([3, 1]) <= s1)
print(Set([3, 2, 4, 1]) == s1)
print(s1 == s2)
print(2 C s1)
print(10 !C s1)
print(Set([1, 2, 3, 4, 5]) > s1)
print(Set([1, 2, 3, 4]) > s1)
print(Set([1, 2, 3, 4]) >= s1)
print(s1.symmetric_difference(s2))
print(s1.len)
s1.add(99)
print(s1)
s1.discard(99)
print(s1)