proposition: Lemma split_entP (A : set (M * M)) : entourage A -> entourage (split_ent A) /\ split_ent A \; split_ent A `<=` A.
proof: Proof. by move/entourage_split_ex/exists2P/getPex. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed