Challenge S/C .. still easy, but hehe...

Let N be the set of all positive integers: N={1,2,3,...}
Let P = {A | A is a subset of N} be the power set of N.
A subset L of P is called a link if for any elements x, y in L, either x is a subset of y or y is a subset of x.
Question: are all links countable?

所有跟帖： 

• P.S. .. this one is not that easy ... actually .. -idiot94- ♂ (0 bytes) () 05/16/2006 postreply 10:57:04

• Uncountable. Proof inside -Commentate- ♂ (344 bytes) () 05/16/2006 postreply 11:35:41

• oh, I think my question might be -idiot94- ♂ (141 bytes) () 05/16/2006 postreply 11:49:19

• Then this question is much easier. -Commentate- ♂ (132 bytes) () 05/16/2006 postreply 12:03:12

• hmm.. no ... take your time, it is not that easy. -idiot94- ♂ (0 bytes) () 05/16/2006 postreply 12:12:14

• Well. -Commentate- ♂ (0 bytes) () 05/16/2006 postreply 12:23:04