fact: Definition comb_exp (R : realDomainType) (s : R) := match sgz s with Posz 1 => 1%N | Negz 0 => 2%N | _ => 0%N end.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice path fintype) mathcomp(div bigop order ssralg poly polydiv ssrnum perm zmodp ssrint) mathcomp(polyorder polyrcf interval matrix mxtens)