Section Properties.
Context {A: Type}.
Definition finite_captured (P: Ensemble A -> Prop): Prop :=
forall (Phi: Ensemble A),
(forall xs: list A, Forall Phi xs -> P (fun x => In x xs)) ->
P Phi.
Definition finite_witnessed (P: Ensemble A -> Prop): Prop :=
forall (Phi: Ensemble A), P Phi ->
exists xs: list A, Forall Phi xs /\ P (fun x => In x xs).
Definition subset_preserved (P: Ensemble A -> Prop): Prop :=
forall (Phi Psi: Ensemble A),
Included _ Phi Psi -> P Psi -> P Phi.
Definition superset_preserved (P: Ensemble A -> Prop): Prop :=
forall (Phi Psi: Ensemble A),
Included _ Phi Psi -> P Phi -> P Psi.

Lemma not_superset_preserved_subset_preserved: forall P,
superset_preserved P ->
subset_preserved (fun X => ~ P X).