Dave Marker : The decidability of the natural numbers with almost-all quantifiers

Posted by Matthias Aschenbrenner , part of the Logic Seminar.

At

Feb. 28, 2006, 4 p.m.

In

SEO 427

Abstract

Consider the theory of the natural numbers where we use the quantifiers "almost all" and "exists unboundedly many" instead of "for all" and "there exists". Ted Slaman proved the surprising result that this theory is decidable. We will show that this result has an easy model theoretic proof.