An apparatus provides hot standby operation with normal and standby processors, each of which includes vital inputs electrically interconnected with the vital inputs of the other processor, vital outputs, and an application routine inputting the vital inputs and outputting the vital outputs. It is a machine which can replicate any form of combat which uses punches, elbows and kicks. The first output drives an input of the second delay stage, which provides a second output. The first stacked body includes a plurality of third layers including AlGaInN, and a plurality of fourth layers alternately stacked with the third layers and including GaInN. The receptor may be a gun-shaped sub-unit with a barrel portion and a gripper portion with an open slot adapted to receive the core unit. The different rolling diameters within the scope of one wheel gives different ground pressures.