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From: homeier@cs.ucla.edu (peter v. homeier)
Message-Id: <9505162347.AA04588@oahu.cs.ucla.edu>
Subject: Question on Dijkstra Quote
To: info-hol@leopard.cs.byu.edu
Date: Tue, 16 May 1995 16:47:35 -0700 (PDT)
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Some time ago I heard that E. W. Dijkstra had once said or written
something to the following effect:

"Testing is fine for showing the presence of errors; 
but it is useless for showing their absence."

Try as I might, I have not been able to pin down the source of
this quote.  Can anyone refer me to an article, book, etc. that I can
reliably quote?  Also, what was the actual, literal quote?

It seems like such a standard part of the folklore that I thought
it would be easy to find, but it hasn't been quickly obvious from the
books I have here.

Thanks!

Peter Homeier
homeier@cs.ucla.edu