proposition: Lemma invRE x : x != 0 -> x^-1 == Real.inv x.
proof: Proof. exact: IFR_else. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)