Hello,
Maxima 5.21.1 as well as 5.23.2, built with Ecl 11.1.1,
has a completely corrupted next_prime function, e.g.
next_prime(113) = 121 = 11^2
(determining all "primes" within {1,...,1000} yields 231
"primes", while there are 168).
Don't know whether this is an Ecl or a Maxima (or a joint) problem.
Would be good to find out.
In any case, it would be good if Maxima had tests which would catch
these failures (for example determining all primes within an interval,
and counting them).
Best regards
Oliver