of sym- bol sequences picked up within the [0, 1) probability interval. The symbol sequences form random bit streams having probability-distribution characteristics departing from uniformity, i.e., p(x1 = 0) # p(x2 = 1). 8 A pseudo-random word can be a pre-established bit pattern with uniform 1/0 bit distribution, which is cyclically repeated by bit translation or permutation. Integer, arithmetic, and adaptive coding Arithmetic coding can also be used for fast data-entry devices. The principle is for a human operator to acquire information and produce a maximum of information bits through a minimal number of body gestures. A computer keyboard only provides the one- to-one correspondence between alphanumerical characters and their ASCII codewords. The keyboard is designed to have the most frequently used letters in specific locations that the ten fingers learn to reach automatically, without searching. Let us imagine instead a fancy dynamic keyboard, where the most frequently used letters and most likely letter groups would always be found near the last character that was entered, like finding he immediately after typing t or nd after a, corresponding to the words the and and, respectively. Ready-made word terminations, like cept, dition, stitute, tinue, vey, and vention, would show up as soon as the text con had been input to the keyboard, for instance. These word terminations could also be arranged according to their frequent use in the specific message context. Such a dynamic keyboard would make it possible to achieve rapid text acquisition using a single-click, perhaps with a mouse or an optical or eye pointer or tracker. A representative application of this principle is provided by the project Dasher (European languages), also named Daishoya (Japanese). It consists of a text-entry interface, which can be driven by natural pointing gestures, using a joystick, a touch-screen, a tracker or roller ball, a mouse, or even an eye tracker. Experienced readers can perform text acquisition with a single finger or eye m