Library Coq.Wellfounded.Inclusion

Require Import Relation_Definitions.

Section WfInclusion.
  Variable A : Type.
  Variables R1 R2 : A -> A -> Prop.

  Lemma Acc_incl : inclusion A R1 R2 -> forall z:A, Acc R2 z -> Acc R1 z.

  Hint Resolve Acc_incl.

  Theorem wf_incl : inclusion A R1 R2 -> well_founded R2 -> well_founded R1.

End WfInclusion.