fact: Definition next_root (p : {poly R}) x b := if p == 0 then x else head (maxr b x) (roots p x b).
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg poly polydiv ssrnum zmodp) mathcomp(polyorder path interval ssrint)