On Fri, Jul 13, 2018 at 4:11 AM, Steven D'Aprano firstname.lastname@example.org wrote:
There is no reason why primality testing can't be deterministic up to 2**64, and probabilistic with a ludicrously small chance of false positives beyond that. The implementation I use can be expected to fail on average once every 18 thousand years if you did nothing but test primes every millisecond of the day, 24 hours a day. That's good enough for most purposes :-)
What about false negatives? Guaranteed none? The failure mode of the function should, IMO, be a defined and documented aspect of it.