proposition: Lemma sin2cos2 x : sin x ^+ 2 = 1 - cos x ^+ 2.
proof: Proof. by move/eqP: (cos2Dsin2 x); rewrite eq_sym addrC -subr_eq => /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