proposition: Lemma eq_creal_refl x : x == x.
proof: Proof. apply: eq_crealP; exists (fun _ => 0%N). by move=> e i e_gt0 _; rewrite subrr normr0. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg ssrnum ssrint rat poly polydiv polyorder) mathcomp(perm matrix mxpoly polyXY binomial bigenough)