I was thinking about this one for a while and can't find a proper function.
let $M=${$A\in P(N)$|A And A' are infinite}
(for example: the set of all even numbers will be in M, the complement of A will be all odd numbers (of N). )
I need to find the cardinal number of M.
so I know that $M\subseteq P(N)\rightarrow|M|\leq|P(N)=C$
now for the other way, what one to one function can I show to M?