## functions in gcd.i - i

is_prime

is_prime(x) return non-zero if and only if X (which must be a scalar integer) is prime. May return a false positive if X is greater than about 3e9, since at most 20000 candidate factors are checked. The absolute value of X is taken first; zero is not prime, but 1 is. Interpreted function, defined at i/gcd.i line 64SEE ALSO: gcd, lcm, factorize