proposition: Lemma mark_near (P : Prop) : locked_with near_key P -> P.
proof: Proof. by rewrite unlock. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap generic_quotient) mathcomp(boolp classical_sets functions) mathcomp(cardinality mathcomp_extra fsbigop) reals signed