proposition: Lemma neq_creal_cst x y : reflect (cst_creal x != cst_creal y) (x != y).
proof: Proof. apply: (iffP idP)=> neq_xy; pose_big_enough i. + by apply (@neq_crealP `|x - y| i i); rewrite ?normr_gt0 ?subr_eq0 . + by close. + by rewrite (@creal_neq_always _ _ i neq_xy). + by close. 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)