From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: bil@ccrma.Stanford.EDU Newsgroups: gmane.lisp.guile.bugs Subject: bug#30426: division inconsistency? Date: Mon, 12 Feb 2018 13:59:24 -0800 Message-ID: <8d11fe9992e70af48db00d9a35a93a20@ccrma.stanford.edu> References: <874lmlrkgc.fsf@netris.org> <87sha5q588.fsf@netris.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Trace: blaine.gmane.org 1518472705 11243 195.159.176.226 (12 Feb 2018 21:58:25 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 12 Feb 2018 21:58:25 +0000 (UTC) User-Agent: Roundcube Webmail/1.0.12 Cc: 30426@debbugs.gnu.org To: Mark H Weaver Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Mon Feb 12 22:58:21 2018 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1elM6x-0001er-Hc for guile-bugs@m.gmane.org; Mon, 12 Feb 2018 22:58:07 +0100 Original-Received: from localhost ([::1]:58513 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1elM8x-0003YY-Lt for guile-bugs@m.gmane.org; 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Mon, 12 Feb 2018 13:59:24 -0800 In-Reply-To: <87sha5q588.fsf@netris.org> X-Sender: bil@ccrma.stanford.edu x-proofpoint-stanford-dir: outbound X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-12_09:, , signatures=0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-12_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=559 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802120278 X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: "bug-guile" Xref: news.gmane.org gmane.lisp.guile.bugs:9005 Archived-At: Thanks very much for the informative answer! I am not sure what (* 0 +nan.0) should return. I lean toward +nan.0 mainly because I assume NaNs exist to indicate an error somewhere, and you want that to be returned. For (* 0 +inf.0) I have no druthers. For (/ 0.0 0) and (/ +nan.0 0) s7 throws a divide-by-zero error, but I have no good reason for doing this. In s7, I'd prefer to say (/ x y ...) is equal to (/ x (* y ...)) in all cases.