proposition: Lemma tan0 : tan 0 = 0 :> R.
proof: Proof. by rewrite /tan sin0 cos0 mul0r. 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