110 likes | 228 Views
How can I send VALENTINES? --- Let me count the ways. SUBSETS. OF MY SET OF FRIENDS. { , , }. { }. { }. { , }. { , }. { }. { , }. S =. { , , }. the POWER SET of S. { }. { , , }. { , , }. { , , }.
E N D
How can I send VALENTINES? --- Let me count the ways. SUBSETS OF MY SET OF FRIENDS
{ , , } { } { } { , } { , } { } { , } S = { , , } the POWER SET of S { }
{ , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } { , , } 2 x 2 x 2
If a set S has n members, then S has 2n subsets. ie: the POWER SET of S has 2n members
When S is a finite set, the power set of S contains more members Than S …….. A finite set has more subsets than members. Cantor proved the same for infinite sets … ie: for any set S, The power set of S has a greater cardinal number than S. We will examine the infinite set N = { 1, 2, 3, 4, 5, ……… } and the power set of N
If there is a one to one correspondence between N and P(N) it would look like this:
2 is NOT a member of S2 3 is NOT a member of S3 5 is NOT a member of S5 7 is NOT a member of S7
2 is NOT a member of S2 3 is NOT a member of S3 5 is NOT a member of S5 7 is NOT a member of S7 Build a set containing all the numbers that do NOT belong to their paired set
2 is NOT a member of S2 3 is NOT a member of S3 5 is NOT a member of S5 7 is NOT a member of S7 Build a set containing all the numbers that do NOT belong to their paired set … call this set Sk and include it in the list of subsets … it must correspond to some natural number k.
Is k a member of Sk ? If it is then it isn’t. If it isn’t then it is. = { m / m is NOT a member of Sm