proposition: Lemma __deprecated__dlet_dmargin (mu : {distr T / R}) (f : T -> U) (g : U -> {distr V / R}): \dlet_(u <- dmargin f mu) g u =1 \dlet_(t <- mu) (g (f t)).
proof: Proof. move=> x; rewrite __deprecated__dlet_dlet; apply: eq_in_dlet=> //. by move=> y _ z; rewrite dlet_unit. Qed.
imports: mathcomp(all_ssreflect all_algebra) mathcomp.classical(boolp classical_sets mathcomp_extra) xfinmap ereal reals discrete topology realseq realsum