(** Recognition of move operations. *)
Definition is_move_operation
(A: Type) (op: operation) (args: list A) : option A :=
match op, args with
| Omove, arg :: nil => Some arg
| _, _ => None
end.

Lemma is_move_operation_correct:
forall (A: Type) (op: operation) (args: list A) (a: A),
is_move_operation op args = Some a ->
op = Omove /\ args = a :: nil.