Well there are two more definitions, from the same book [1], that are not equivalent: pp. 335 For all natural numbers x, if x is even, non-zero, and not 2, then there exist prime numbers y and z such that x is the sum of y and z. pp. 673 ...every even number, n>6 (it at least takes care of my question about 4), is the sum of two odd primes. ____________________________________________________________________ Lawyers ask the wrong questions when they don't want the right answers. Scully (X-Files) The Armadillo Group ,::////;::-. James Choate Austin, Tx /:'///// ``::>/|/ ravage@ssz.com www.ssz.com .', |||| `/( e\ 512-451-7087 -====~~mm-'`-```-mm --'- -------------------------------------------------------------------- [1] VNR Concise Encyclopedia of Mathematics