It seems mpz_probably_prime_p considers negated primes to also be prime.
E.g, for n == -29 it returns 2, meaning definitely prime.
Mathematically, I think -29 is usually considered neither prime, nor
composite (its prime factorization is -1 * 29 and the unit factor -1
kind-of doesn't count, since
ni...@lysator.liu.se (Niels Möller) writes:
It seems mpz_probably_prime_p considers negated primes to also be prime.
E.g, for n == -29 it returns 2, meaning definitely prime.
Mathematically, I think -29 is usually considered neither prime, nor
composite (its prime factorization is -1 * 29
Ciao,
Il Lun, 3 Marzo 2014 11:08 pm, Torbjorn Granlund ha scritto:
ni...@lysator.liu.se (Niels Möller) writes:
It seems mpz_probably_prime_p considers negated primes to also be prime.
I agree they are.
On rings I usually take the following definition for primes:
p is prime if and only if p
