fact: Definition good_for_cf a l:= [&& rat_in_Z a, all rat_in_P l & last 0 l !=1].
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)