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Date: Tue, 16 May 1995 17:57:25 -0700
From: heckman@cs.ucdavis.edu (Mark R. Heckman)
Message-Id: <9505170057.AA12766@shangrila.cs.ucdavis.edu>
To: homeier@cs.ucla.edu, info-hol@leopard.cs.byu.edu
Subject: Re: Question on Dijkstra Quote

>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."

In a similar vein, I once read a second-hand quote attributed to
Knuth that said "Beware of bugs in the above code.  I have only
proven it correct; I haven't tried it yet."  Can anyone help me
find the source of this quote?

Thanks,

Mark Heckman
heckman@cs.ucdavis.edu