Global Instance type_Prop : type Prop :=
{ equal := iff
; proper := fun _ => True
}.
Global Instance typeOk_Prop : typeOk type_Prop.

(** NOTE: These should fit into a larger picture, e.g. lattices or monoids **)
(** And/Conjunction **)
Lemma and_True_iff : forall P, (P /\ True) <-> P.