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Re:Do we have negative prime numbers? by giomasce on Saturday January 16, 2021 @01:47PM (#25804327)
Hey, didn't notice the nick! Hi!

Well, if you're speaking about non-negative integers, you don't have the problem of the primality of negative numbers.

If you're considering relative integers, still you don't really have a unique factorization property, because negative integers do not have a factorization altogether (in terms of positive primes). So you have to stipulate that a prime factorization is not just a "product of primes", but a "product of primes, perhaps times -1", which is still not the way you usually define it. So I am not totally convinced.

In the end, everybody just pick the definition they like.

Re:Do we have negative prime numbers? by ot on Saturday January 16, 2021 @02:00PM (#25804436)
I've definitely seen the definition

x = u p_1 p_2 ...

where u is any unity, but I agree that people pick the definition they need depending on the context.