From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: Elisp manual, node "Comparison of Numbers" Date: Mon, 29 May 2006 17:28:38 -0400 Message-ID: References: <85fyitc5w4.fsf@lola.goethe.zz> Reply-To: rms@gnu.org NNTP-Posting-Host: main.gmane.org Content-Type: text/plain; charset=ISO-8859-15 X-Trace: sea.gmane.org 1148938161 573 80.91.229.2 (29 May 2006 21:29:21 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Mon, 29 May 2006 21:29:21 +0000 (UTC) Cc: drew.adams@oracle.com, emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon May 29 23:29:10 2006 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by ciao.gmane.org with esmtp (Exim 4.43) id 1FkpID-0006Pl-Ba for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 23:28:53 +0200 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1FkpIC-0004Tv-L0 for ged-emacs-devel@m.gmane.org; Mon, 29 May 2006 17:28:52 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1FkpI1-0004Te-Qw for emacs-devel@gnu.org; Mon, 29 May 2006 17:28:41 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1FkpI1-0004TQ-8m for emacs-devel@gnu.org; Mon, 29 May 2006 17:28:41 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1FkpI1-0004TN-37 for emacs-devel@gnu.org; Mon, 29 May 2006 17:28:41 -0400 Original-Received: from [199.232.76.164] (helo=fencepost.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.52) id 1FkpNe-00087w-Vw for emacs-devel@gnu.org; Mon, 29 May 2006 17:34:31 -0400 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.34) id 1FkpHy-0004OI-EE; Mon, 29 May 2006 17:28:38 -0400 Original-To: David Kastrup In-reply-to: <85fyitc5w4.fsf@lola.goethe.zz> (message from David Kastrup on Mon, 29 May 2006 15:33:31 +0200) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:55451 The problem here is that fuzz is a _relative_ measure of equality, and you employ it as an absolute measure here. That is true -- but, in the case where one of the numbers is zero, we have no way to apply a relative criterion to the other number. There is no possible standard for it to be relative to. Perhaps the idea of approximate equality can't be applied to the case where either of the numbers is zero. Perhaps it should always return nil in that case. If so, the current definition is correct, though not written very clearly for the result it gives.