Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site brl-tgr.ARPA Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!hao!seismo!brl-tgr!gwyn From: gwyn@brl-tgr.ARPA (Doug Gwyn ) Newsgroups: net.unix-wizards Subject: Re: more sun and vax diffs Message-ID: <4497@brl-tgr.ARPA> Date: Sat, 8-Sep-84 21:28:57 EDT Article-I.D.: brl-tgr.4497 Posted: Sat Sep 8 21:28:57 1984 Date-Received: Fri, 14-Sep-84 09:07:12 EDT References: <404@wdl1.UUCP> Organization: Ballistics Research Lab Lines: 15 "Log10 of zero IS infinity." That is a good example of the problem with trying to support arithmetic on non-numbers. The quoted statement is incorrect in any case, since 10 ^ infinity is definitely not zero. I would also object to the more correct statement "Log10 of zero is minus infinity", if infinity is being treated on an equal basis with real numbers. Correct treatment of infinite and infinitesimal quantities is the province of the field of "nonstandard analysis", and these simplistic approaches will just get na"ive users into trouble. Let me ask another one: What is the square root of -1? Anyone who says "i" or "-i" is wrong; the square root is a double-valued function and must be treated VERY carefully or bogus answers will be obtained. This is explained in any good complex analysis course.