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From: STCS8004%IRUCCVAX.UCC.IE@mitvma.mit.EDU
Newsgroups: comp.lang.scheme
Subject: Kleene puzzle
Message-ID: <9104100752.aa25783@mc.lcs.mit.edu>
Date: 10 Apr 91 12:41:00 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
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A few news-letters back the following problem was posted:

  What is the shortest program that writes itself to the output port.
  The value of the program is not of concern, only the side-effect of
  the output.

I regret  that I  have lost  reference  to  the original  question and  the
solutions  proposed, but  if my  memory serves  me correctly  the solutions
involved  the use  of let  statements. I  believe the  following program is
shorter than  those previously proposed both  in terms of symbols  and cons
operations:

  ((lambda (x) (write `(,x ',x)))
   '(lambda (x) (write `(,x ',x))))

This is simply the 'write' version the shorter self-evaluating program

  ((lambda (x) `(,x ',x))
   '(lambda (x) `(,x ',x))).


G. Oulsnam                                    stcs8004@iruccvax.ucc.hea.ie