交换律:$A \cup B = B \cup A,A \cap B = B \cap A$
结合律:$(A \cup B) \cup C = A \cup (B \cup C),(A \cap B) \cap C = A \cap (B \cap C)$
分配律:$(A \cup B) \cap C = (A \cap C) \cup (B \cap C),(A \cap B) \cup C = (A \cup C) \cap (B \cup C)$
对偶律:$(A \cup B)^c = A^c \cap B^c,(A \cap B)^c = A^c \cup B^c$