proposition: Lemma measureIl : mu (A `&` B) <= mu A.
proof: Proof. by rewrite le_measure ?inE//; apply: measurableI. Qed.
imports: mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) reals ereal signed topology normedtype sequences esum numfun HB(structures)