proposition: Lemma le1_pr A mu : \P_[mu] A <= 1.
proof: Proof. apply/(@le_trans _ _ \P_[mu] predT). by apply/subset_pr. by rewrite pr_predT le1_mu. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum