(* Lemma headptr_field_compatible' {cs: compspecs}: forall t p, headptr p -> legal_alignas_type t = true -> legal_cosu_type t = true -> sizeof t < Ptrofs.modulus -> complete_type cenv_cs t = true -> field_compatible t nil p. *)

Lemma mapsto_data_at'' {cs: compspecs}: forall sh t v v' p,
((type_is_by_value t) && (complete_legal_cosu_type t) && (negb (type_is_volatile t)) && is_aligned cenv_cs ha_env_cs la_env_cs t 0 = true)%bool ->
headptr p ->
JMeq v v' ->
mapsto sh t p v = data_at sh t v' p.