proposition: Lemma measurable_set1y : G.-sigma.-measurable [set +oo].
proof: Proof. rewrite eset1y; apply: bigcap_measurable => i _. rewrite -setCitvl; apply: measurableC; rewrite (eitv_infty_bnd true). apply: bigcap_measurable => j _; rewrite -setCitvr; apply: measurableC. by apply: sub_sigma_algebra; exists (i%:R + j.+1%:R^-1)%R. Qed.
imports: mathcomp(all_ssreflect ssralg ssrnum ssrint interval) mathcomp(finmap fingroup perm rat) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop) reals ereal signed topology numfun normedtype HB(structures) sequences esum measure real_interval realfun exp lebesgue_stieltjes_measure