next_prime is very slow (in comparisation with for example GMP)
I included a small and simple fix that uses the same "algorithm" as GMP
old execution time: 8s
with fix: 3s
Any interest in including this fix? If so, i'm willing to improve it a lot more (and improve prev_prime also).
this is a patch for "maxima/src/ifactor.lisp": cd maxima/src/ && patch < ifactor.diff