Section EUTTG_principles.
Context {E : Type -> Type} {R1 R2 : Type} (RR : R1 -> R2 -> Prop).
Local Notation euttG := (@euttG E R1 R2 RR).
(* Make new hypotheses *)
(* Process itrees *)
(* Drop weak hypotheses for general rewriting *)
(* Make a weakly guarded progress *)
(* Make a strongly guarded progress *)
(* Use available hypotheses *)

Lemma euttG_base: forall rH rL gL gH t1 t2,
rH t1 t2 \/ rL t1 t2 -> euttG rH rL gL gH t1 t2.