Section STRONGER.
Context {cs: compspecs}.
Definition stronger {t: type} (v v': reptype t) : Prop :=
forall sh, data_at sh t v |-- data_at sh t v'.
Definition data_equal {t} v1 v2 := forall sh, data_at sh t v1 = data_at sh t v2.
Notation "X '>>>' Y" := (stronger X Y) (at level 60, no associativity).
Notation "X '===' Y" := (data_equal X Y) (at level 60, no associativity).

Lemma eq_rect_r_stronger: forall {t1 t2} v0 v1 (H: t1 = t2),
v0 >>> v1 ->
eq_rect_r reptype v0 H >>> eq_rect_r reptype v1 H.