Before revision: We investigate a class of multi-object rearrangement problems in which a robotic manipulator, capable of carrying an item and making item swaps, is tasked to sort items stored in lattices  in a time-optimal manner.
After revision: We propose and study a class of multi-object rearrangement problems in which a robotic manipulator, capable of carrying an item and making item swaps, is tasked to sort items stored in lattices in a time-optimal manner.