Re: Line numbers

[Guy.Steele at CMU-10A]

Right on!  But single-letter names are few in number.  How
about optionally appending a digit?  So here is factorial:
(DEFUN FACT (N)
   (PROG (A)
    10   (SETQ A 1)
    20   (IF (= N 0) (RETURN A))
    30   (SETQ A (* N A))
    40   (SETQ N (- N 1))
    50   (GO 20)))
[You think that's funny, hah?!  Well, it really is a legal MacLISP
program, and it will work!]
If you prefer recursion to iteration, then how about:
(DEFUN FACT (N)
   (PROG (A)
    10   (SETQ A 1)
    20   (IF (= N 0) (RETURN A))
    30   (SETQ N (- N 1))
    40   (GOSUB 20)
    50   (SETQ N (+ N 1))
    60   (SETQ A (* N A))
    70   (RETURN A)))
[Not legal MacLISP... yet!]