Defined.
Global Arguments Acc_inv [x] _ [y] _, [x] _ y _.
Register Acc_inv as core.wf.acc_inv.
(** A relation is well-founded if every element is accessible *)
Definition well_founded := forall a:A, Acc a.
Register well_founded as core.wf.well_founded.
(** Well-founded induction on [Set] and [Prop] *)
Hypothesis Rwf : well_founded.

Theorem well_founded_induction_type :
forall P:A -> Type,
(forall x:A, (forall y:A, R y x -> P y) -> P x) -> forall a:A, P a.