proposition: Lemma sinDpi : alternating sin pi.
proof: Proof. by move=> a; rewrite sinD cospi mulrN1 sinpi mulr0 addr0. 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