fact: Fixpoint abs_pol (l:list rat) :list rat := match l with nil => nil | a::tl => `|a| :: abs_pol tl end.
imports: ZArith Zwf Lia mathcomp(ssreflect eqtype ssrbool ssrnat div fintype seq ssrfun order) mathcomp(bigop fingroup choice ssralg ssrnum rat poly) pol