proposition: Lemma add_creal0 x : x + 0 == x.
proof: Proof. by apply: eq_crealP; exists m0=> * /=; rewrite addr0 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)