proposition: Lemma pi_ge0 : 0 <= pi.
proof: Proof. exact: (ltW pi_gt0). 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