Here is the proof I was looking for
I found a proof in Suppes, Axiomatic Set Theory, pp. 104-105 that
doesn't use natural number exponentiation, and this is what I was
looking for. Here is an outline, using u = union and - = set difference.
We use induction on the cardinality of x. The...
Hi, I'm the OP, and thanks for all the responses - glad to see this
forum is so active.
To clarify a little bit, I understand intuitively that if x ~ n then Px
~ 2^n and thus is obviously finite. But what I was wondering is whether
there is a direct set-theoretical proof that doesn't...