prime:prngs is the random-state (see Random Numbers) used by these procedures. If you call these procedures from more than one thread (or from interrupt),
randommay complain about reentrant calls.
Returns the value (+1, −1, or 0) of the Jacobi-Symbol of exact non-negative integer p and exact positive odd integer q.
prime:trials the maxinum number of iterations of Solovay-Strassen that will be done to test a number for primality.
Returns
#fif n is composite;#tif n is prime. There is a slight chance(expt 2 (- prime:trials))that a composite will return#t.