Remark decompose_int_arm_nil:
  forall N n p, decompose_int_arm N n p = nil -> n = Int.zero.

(* Specifications: *)
Lemma decompose_int_thumb_or: forall N n p x, List.fold_left Int.or (decompose_int_thumb N n p) x = Int.or x n.
Lemma decompose_int_thumb_xor: forall N n p x, List.fold_left Int.xor (decompose_int_thumb N n p) x = Int.xor x n.
Lemma decompose_int_thumb_add: forall N n p x, List.fold_left Int.add (decompose_int_thumb N n p) x = Int.add x n.