fact: Definition hornerE := (hornerD, hornerN, hornerX, hornerC, horner_exp, simp, hornerCM, hornerZ, hornerM, horner_cons).
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)