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From: ok@cs.mu.oz.au (Richard O'Keefe)
Newsgroups: comp.lang.misc
Subject: Re: swap(x,y) in Algol 60
Keywords: swap, algol
Message-ID: <2012@munnari.oz.au>
Date: 4 Sep 89 06:51:55 GMT
References: <31690@cornell.UUCP> <8369@boring.cwi.nl> <31736@cornell.UUCP> <31751@cornell.UUCP>
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There is a formal proof.  I believe it was published in the Algol Bulletin,
but it has been about six years since I read it.  You might look through
the Amsterdam MC (now CWI) reports as well.