Definition full_hist h v := exists l, hist_list h l /\ apply_hist (vint 0) l = Some (vint v).
Definition full_hist' h v := exists l, hist_list' h l /\ apply_hist (vint 0) l = Some v.

Lemma full_hist_weak : forall h v (Hl : full_hist h v), full_hist' h (vint v).