A video decoder decodes a video signal based on a down conversion function. A function whose function set value is to be displayed on a function setting screen is identified from identifying information included in screen information made by the information processing apparatus. The image surface is positioned within the inner diameter of the axicon mirror. A synthetic synapse is also provided. The process can include regenerating a catalyst in a regenerator, separating particulate solids in first and second cyclone stages, passing the gas stream from the second cyclone stage to an external third stage separator, and passing the gas stream from the external third stage separator to a cyclone recirculator to obtain a clean gas stream.