Definition bmatch (m: mem) (b: block) (ab: ablock) : Prop :=
  smatch m b ab.(ab_summary) /\
  forall chunk ofs v, Mem.load chunk m b ofs = Some v -> vmatch v (ablock_load chunk ab ofs).

Lemma ablock_loadbytes_sound: forall m b ab b' ofs' q i n ofs bytes, Mem.loadbytes m b ofs n = Some bytes -> bmatch m b ab -> In (Fragment (Vptr b' ofs') q i) bytes -> pmatch b' ofs' (ablock_loadbytes ab).