Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: A finite set of all naturals
Replies: 15   Last Post: Aug 17, 2013 3:10 AM

 Messages: [ Previous | Next ]
 Virgil Posts: 8,833 Registered: 1/6/11
Re: A finite set of all naturals
Posted: Aug 16, 2013 3:33 PM

In article <c10s09pu0gs0av09l4gfqrrpbdm5gj510n@4ax.com>,
quasi <quasi@null.set> wrote:

> quasi wrote:
> >
> >
> > odd(x) <-> [x*y=2*z] -> Ew[y=2*w]

>
> to Nam:
>
> Since you've has already defined various versions of even(x),
> my above definition of odd(x) can be expressed more simply as:
>
> odd(x) <-> even(x*y) -> even(y)
>
> Doesn't that qualify as a "positive formula"?
>
> quasi

I like that one!
--

Date Subject Author
8/15/13 Ben Bacarisse
8/16/13 Virgil
8/16/13 namducnguyen
8/16/13 antani
8/16/13 namducnguyen
8/16/13 Peter Percival
8/16/13 Peter Percival
8/16/13 Ben Bacarisse
8/16/13 quasi
8/16/13 quasi
8/16/13 Virgil
8/17/13 namducnguyen
8/17/13 Virgil
8/17/13 Peter Percival