proposition: Lemma pi_gt0 : 0 < pi.
proof: Proof. by rewrite (lt_le_trans _ pi_ge2). 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