proposition: Lemma derivable_sin x : derivable sin x 1.
proof: Proof. by apply: ex_derive; apply: is_derive_sin. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(mathcomp_extra boolp classical_sets functions) reals ereal nsatz_realtype signed topology normedtype landau sequences derive realfun exp