Module MemoryWD.
(** Valid memories are the ones that do not contain any dangling pointers*)
Definition valid_mem m :=
forall b,
Mem.valid_block m b ->
forall ofs mv,
Maps.ZMap.get ofs (Mem.mem_contents m) # b = mv ->
match mv with
| Fragment v q n =>
mem_wd.val_valid v m
| _ => True
end.

Lemma decode_val_wd:
forall f (vl : seq memval) (chunk : memory_chunk),
valid_memval_list f vl ->
valid_val f (decode_val chunk vl).