Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed1a.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.037 X-Spam-Evidence: '*H*': 0.93; '*S*': 0.00; 'modulo': 0.09; 'raises': 0.09; 'subject:Why': 0.09; 'missed': 0.12; 'discussed.': 0.16; 'infinity': 0.16; 'infinity,': 0.16; 'zero,': 0.16; 'wrote:': 0.18; 'wed,': 0.18; 'define': 0.26; 'header:In-Reply-To:1': 0.27; 'point': 0.28; 'chris': 0.29; 'am,': 0.29; 'message- id:@mail.gmail.com': 0.30; "i'm": 0.30; 'sep': 0.31; 'received:google.com': 0.35; 'really': 0.36; 'to:addr:python- list': 0.38; 'issue': 0.38; 'anything': 0.39; 'sure': 0.39; 'to:addr:python.org': 0.39; 'number,': 0.60; 'natural': 0.68; 'anything.': 0.68; 'divided': 0.91; 'serious': 0.97 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=qbRobJQgS4i76+UJXyqkdw4N0XudH99bYRWEGFBmJKk=; b=pPMb3nR2kVRW0E5zztqahhq5PPGau5oAujnGjCYCaqiGxF73yd5avwiLBZe5YsaxZ/ XW471j73NKdpLy67BgGwOCCfptmmsmxzRg1ZgRQqBmLB61QXpKS46Qst5emtRCooWW18 8bbs0VFWISFPbr95vhtsgH9q/zpa+eKnQEHAVVhd5D4BCsZobs4A2kvE17syqzFiecGX C+bmsi3DDunhLccH0KdakvzFv50FoWV5/dy27FnpSdhD4osgcygkcFSUTzzAVMOnanXd 86N7/BlzCNgK0jNuOmibIqzalHygji6W6cXwUoo/9CbdbzKZmTZjUPMO2EIyXPi/elZC BtWA== X-Received: by 10.180.211.36 with SMTP id mz4mr42614907wic.39.1410977047440; Wed, 17 Sep 2014 11:04:07 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <06397cb3-8baf-4af1-8152-ff7c3f6ceb62@googlegroups.com> From: Ian Kelly Date: Wed, 17 Sep 2014 12:03:27 -0600 Subject: Re: Why `divmod(float('inf'), 1) == (float('nan'), float('nan'))` To: Python Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 10 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1410977055 news.xs4all.nl 2958 [2001:888:2000:d::a6]:37455 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:77980 On Wed, Sep 17, 2014 at 9:10 AM, Chris Angelico wrote: > And while it's > conceivable to define that infinity divided by anything is infinity, > and infinity modulo anything is zero, that raises serious issues of > primality and such; I'm not sure that that would really help anything. I missed that this point was already discussed. Can you elaborate on the "serious issues of primality and such"? Since infinity is not a natural number, its primality is undefined, so I don't see the issue here.