proposition: Lemma expRxMexpNx_1 x : expR x * expR (- x) = 1.
proof: Proof. by rewrite -[X in _ X * _ = _]addr0 expRxDyMexpx expR0. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(boolp classical_sets functions) mathcomp(mathcomp_extra) reals ereal signed topology normedtype landau sequences derive realfun itv convex