Define: x.y = product of x and y
a,b denote 1,2 respectively
X|Y= x divides y
Ex = x is even
Ox = x is odd
Pr(x? = x is a prime number
define using times as function symbol . is two place symbol
f(x;y) = x -y
Express the gold bach theorem : every even whole number other than two is the sum of two primes . Express this conjective in terms of times for product and a,b ,( use prime number defination in terms of times).