chars = {"A", "B", "C", "D"}
contain_a = "A" in chars
# contain_a is True
contain_e = "E" in chars
# contain_e is False
chars2 = {"A", "B"}
# Superset or equal
contain_all = chars >= chars2
# contain_all is True
print(f"{contain_a = }")
print(f"{contain_e = }")
print(f"{contain_all = }")