proposition: Lemma pr_exp mu (E : pred T) : \P_[mu] E = \E_[mu] (fun m => (E m)%:R).
proof: Proof. by rewrite /pr psum_sum // => x; rewrite mulr_ge0 // ler0n. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum