Abstract: A graphical machine-user interface includes a processor connected to a display screen to generate a screen display of individual items in groups together with the selector indication. The processor and a display screen are used to advantage to provide a rich keyboard function from a very limited set of pushbuttons. For example, five pushbuttons indicating "up", "right", "down", "left", and "middle" are recursively used to reduce a large two-dimensional matrix of item choices presented on the display to some subset, e.g., a top, right, bottom, left, or middle subset. If the reduction results in a choice of one, then that item is selected and output automatically. If the reduction results in a subset with more than one item, then a recursive process is used in which the selection process is repeated until the selected subset is reduced to a single item.