Sentence:  A hypertext such as "Afternoon" (Joyce 1990) will have a fixed number of scriptons (and <WSD>textons</WSD>), while the game "Adventure" (Crowther and Woods 1976) will have a fixed set of <WSD>textons</WSD> but a variable number of scriptons (<WSD>texton</WSD> cominations), determined by the progress of the play. In a MUD, where other concurrent users can type in anything, the number of <WSD>textons</WSD> is not known. 
Meaning of the word marked with <WSD> tags:  (dynamic text) A string of text that acts like a variable, from which the scriptons of a dynamic text are assembled.