[FOM] Replacement

[Thomas Forster]

Well, it depends on your implementation of pairing.  Cartesian products 
can be poroved to exist in Zermelo set theory if you use Winer-Kuratowski 
pairs.  Mathias has a delightful short proof that replecement follows from 
the assertion that the cartesian produc x \times y exists for all x and y 
and all implementations of pairing.

On Thu, 16 Aug 2007, Jan Pax wrote:

> Even the existence of cartesian product requires replacement.
> Correct me if I'm false.
> 
-- 
Home page: www.dpmms.cam.ac.uk/~tf; dpmms phone +44-1223-337981. 
In NZ until october work ph +64-3367001 and ask for extension 8152.
Mobile in NZ +64-21-0580093 (Mobile in UK +44-7887-701-562).