yet more primes

[Mitchell Harris]

On Wed, 3 Dec 2003, Jon Awbrey wrote:
>
> didn't there used to be something like
> a 26 variable logical formula that
> defines primes?

A system of Diophantine equations in 26 variables whose solution set 
involves one variable being exactly the set of primes:

for the equations:

  http://mathworld.wolfram.com/PrimeDiophantineEquations.html

for the original paper and proof:

  James P. Jones, Daihachiro Sato, Hideo Wada, and Douglas Wiens. 
  Diophantine Representation of the Set of Prime Numbers.
  American Mathematical Monthly, 83(6):449--464, June--July 1976

Mitch