# New mpz_trial_division

**Jason Moxham
**
J.L.Moxham@maths.soton.ac.uk

*Sat, 16 Nov 2002 10:16:04 +0000*

How about these two new functions , this should satisfy everyone ?
unsigned long=20
mpz_exist_small_factor(mpz_srcptr N, unsigned long start, unsigned long s=
top)
returns r which is a factor of N between start and stop inclusive and not=
=20
trivial . or returns 0 if no such factor exists.
unsigned long=20
mpz_trial_div(mpz_srcptr N, unsigned long start, unsigned long stop)
returns r which is the smallest prime factor of N between start and stop=20
inclusive , or returns 0 if no such factor exists.
Precondition is that N is not divisible by any number from 2 to start-1