sot 集合 定理1:A=B当且仅当AcB∧BcA 定理2:对任意的集合A,AgA 定理3:对任意的集合A、B、C 如果AcB,BcC,则AgC 定理4:对任意的集合A,⑦cA 定理5:空集是唯一的 2/24/202111:15PM Deren Chen Zhejiang univ 11
S e t s 集合 2/24/2021 11:15 PM Deren Chen, Zhejiang Univ. 11 定理1：A = B 当且仅当A B B A 定理2：对任意的集合A， A A 定理3：对任意的集合A、B、C， 如果 A B， B C，则 A C 定理4：对任意的集合A， A 定理5：空集是唯一的
DEFINITION 3 80t8 集合 The set u is said to be a universal set U={x|x∈P(x)V~(x∈P(x)) 全集 2/24/202111:15PM Deren Chen Zhejiang univ
S e t s 集合 2/24/2021 11:15 PM Deren Chen, Zhejiang Univ. 12 DEFINITION 3. The set U is said to be a universal set : U = {x | xP(x) V (x P(x) )} 全集
DEFINITION 4 80t8 集合 Let s be a set. If there are exactly n distinct elements in S where n is a nonnegative integer, we say that s is a finite set and that n is the cardinality of s The cardinality of S is denoted by IS I 集合的基、势 2/24/202111:15PM Deren Chen Zhejiang univ 13
S e t s 集合 2/24/2021 11:15 PM Deren Chen, Zhejiang Univ. 13 DEFINITION 4. Let S be a set. If there are exactly n distinct elements in S where n is a nonnegative integer, we say that S is a finite set and that n is the cardinality of S. The cardinality of S is denoted by ∣S∣. 集合的基、势
EXAMPLE7 80t8 集合 Let a be the set of odd positive integers less than 10. Then A=5 2/24/202111:15PM Deren Chen Zhejiang univ 14
S e t s 集合 2/24/2021 11:15 PM Deren Chen, Zhejiang Univ. 14 EXAMPLE 7 Let A be the set of odd positive integers less than 10. Then ︱A︱ = 5
EXAMPLE 8 80t8 集合 Let s be the set of letters in the english lphabet Then S= 26 2/24/202111:15PM Deren Chen Zhejiang univ
S e t s 集合 2/24/2021 11:15 PM Deren Chen, Zhejiang Univ. 15 EXAMPLE 8 Let S be the set of letters in the English alphabet. Then ︱S︱= 26