From: rjh@cpax.org.uk   
      
   On 14/12/2022 1:23 pm, Stefan Ram wrote:   
   > Richard Heathfield  writes:   
   >> Your problem is closely related to the very first question I was   
   >> ever posed (in early 1982), by a friend who needed to be able to   
   >> establish cleanly in a single expression whether a keypress was a   
   >> digit (ASCII 48-57). The relevant dialect of BASIC didn't have   
   >> anything like an isdigit function.   
   >> The friend was on the point of giving up on me when I handed him   
   >>                   ABS(K-52.5)<4.5   
   >   
   >    "K >= 48 AND K <= 57" also is a single expression in BASIC.   
      
   The available keywords were LET, PRINT, END, FOR...NEXT, GOTO,   
   GOSUB...RETURN, IF...THEN line number, DEF, READ, DATA, DIM, and   
   REM. AND was not amongst them. Also available were these   
   functions: ABS, ATN (arc tan), COS, EXP, INT, LOG, RND, SIN, SQR   
   (root).   
      
   --   
   Richard Heathfield   
   Email: rjh at cpax dot org dot uk   
   "Usenet is a strange place" - dmr 29 July 1999   
   Sig line 4 vacant - apply within   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)