An approach to performing graph-based computation uses one or both of an efficient startup approach and efficient control using process pools. The surface cleaning apparatus comprises a main body comprising a front end and a rear end, first and second opposed sidewalls and a suction motor housing. The chain guide assemblies can describe straight segments as well as circle segments. Methods for game play may include placing a player mover on a pathway, changing one or more pathways by moving the selectively movable surface from one position to another, and moving the player mover from one board element to the other board element along the continuous pathway. In one embodiment, a process for forming the electronic device uses the second electrode as a hardmask when removing portions of the first organic layer.