proposition: Lemma sin1cos0 x : `|sin x| = 1 -> cos x = 0.
proof: Proof. by move/eqP; rewrite norm_sin_eq1 => /eqP. 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