19. In an information processing system, means for compressing textual information, comprising: means for storing a table relating text characters and associated contexts of a text with corresponding code characters, said table including, for each context of the language of said text, an associated relative alphabet containing said text characters occurring in association with said contexts of said language, and wherein each of said text characters of each of said relative alphabets is associated with a said corresponding code character, means for reading in succession each character and an associated context of a text, and means responsive to said reading means for selecting and reading from said table, for each said text character and associated context, a corresponding code character and providing said code characters to comprise said text in compressed form.
19. In an information processing system, means for compressing textual information, comprising: means for storing a table relating text characters and associated contexts of a text with corresponding code characters, said table including, for each context of the language of said text, an associated relative alphabet containing said text characters occurring in association with said contexts of said language, and wherein each of said text characters of each of said relative alphabets is associated with a said corresponding code character, means for reading in succession each character and an associated context of a text, and means responsive to said reading means for selecting and reading from said table, for each said text character and associated context, a corresponding code character and providing said code characters to comprise said text in compressed form. 20. The compressing means of claim 19, wherein: each of said code characters are selected from a set of code characters shared by said relative alphabets.