Definition A2P {A} :=
 (fun (pmap : access_map) (a : address * A) =>
      let (a0, _) := a in let (b0, ofs0) := a0 in setPermBlock (Some Writable) b0 ofs0 pmap LKSIZE_nat).

Lemma find_too_small A y a x l : (AddressOrdered.lt y a \/ AddressOrdered.eq y a) -> Sorted (AMap.Raw.PX.ltk (elt:=A)) l -> HdRel (AMap.Raw.PX.ltk (elt:=A)) (a, x) l -> AMap.Raw.find (elt:=A) y l = None.