Path: csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!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 0.059 X-Spam-Evidence: '*H*': 0.88; '*S*': 0.00; 'cc:addr:python-list': 0.11; 'jan': 0.12; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'instead:': 0.16; 'sequence:': 0.16; 'yay': 0.16; 'zeroes': 0.16; ':-)': 0.16; 'wrote:': 0.18; 'result.': 0.19; 'work,': 0.20; 'example': 0.22; 'saying': 0.22; 'cc:addr:python.org': 0.22; 'fairly': 0.24; 'cc:2**0': 0.24; 'header:In-Reply-To:1': 0.27; "doesn't": 0.30; 'message- id:@mail.gmail.com': 0.30; "i'm": 0.30; 'work.': 0.31; "d'aprano": 0.31; 'steven': 0.31; 'subject:numbers': 0.31; 'subject:other': 0.31; 'becomes': 0.33; 'fri,': 0.33; 'could': 0.34; 'beyond': 0.35; 'but': 0.35; 'received:google.com': 0.35; 'pm,': 0.38; 'does': 0.39; 'simply': 0.61; "you're": 0.61; 'first': 0.61; 'effectively': 0.66; 'therefore': 0.72; 'obvious': 0.74; 'special': 0.74; '2015': 0.84; 'multiplying': 0.84; 'to:none': 0.92 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=Ue2ZDFvWPAMwgW2KhtaNeK8HvX0S4TomOPf9ofm5eBw=; b=IkmA75HnButNr6XBmW5VD96I9Kjo/DDG9nDoFsyQyN1+x7XHZRRwzToXh29J/gAFbw FR8PFr9+Bgh/KfmLKKgWcM9DhrDCgwlc1rkRBKF6X+0WzmyTnWVJpbhA9qmgkyLUrDf8 BKhH+KIGbcl26uRmlg/7O3+Ni0UzI8lM+X18PadbV8LYD4AFQFJVDHrXCOahM+iMk79/ TImdI0ULHLu3NVxDeJlGQQNCAIZJxAhWiPC6aXnP2OPTOPrWd+yNoUBcpMoDrRf9fWKc dQACYBv00ta3Y4DeScsvJtBv7duXbww2v3Jk0/C6sEIIUlbEJ7FaqKg/tQ2BDOLqR3+x mmQg== MIME-Version: 1.0 X-Received: by 10.50.62.104 with SMTP id x8mr2139018igr.2.1420806863663; Fri, 09 Jan 2015 04:34:23 -0800 (PST) In-Reply-To: <54afc884$0$12985$c3e8da3$5496439d@news.astraweb.com> References: <54AF405C.6020609@davea.name> <54af9612$0$12995$c3e8da3$5496439d@news.astraweb.com> <54afab5d$0$12976$c3e8da3$5496439d@news.astraweb.com> <54afc884$0$12985$c3e8da3$5496439d@news.astraweb.com> Date: Fri, 9 Jan 2015 23:34:23 +1100 Subject: Re: Decimals and other numbers From: Chris Angelico Cc: "python-list@python.org" 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: 33 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1420806865 news.xs4all.nl 2848 [2001:888:2000:d::a6]:48624 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:83436 On Fri, Jan 9, 2015 at 11:24 PM, Steven D'Aprano wrote: >> 5 * 0 * 0 * 0 * 0 = 0 > > Where did the 5 come from? > > You're effectively saying that 0**0 becomes 5*0**0, then cancelling the 0**0 > because they're all zeroes and so don't matter, leaving 5. And that simply > doesn't work. If it did work, there's nothing special about 5, we could use > 18 instead: > > 0**0 = 5*0**0 => 5 > > but 0**0 = 18*0**0 => 18 > therefore 5 = 18. > > Yay maths! :-) To clarify, I'm following this sequence: 5 * 0**4 = 5 * 0 * 0 * 0 * 0 = 0 5 * 0**3 = 5 * 0 * 0 * 0 = 0 5 * 0**2 = 5 * 0 * 0 = 0 5 * 0**1 = 5 * 0 = 0 5 * 0**0 = 5 = ? Multiplication by zero is idempotent; any number of multiplications beyond the first won't change the result. But that doesn't mean that never multiplying by zero will have the same result. I think it's fairly obvious in this example that the pattern does NOT continue to the case where you're multiplying in no zeroes. ChrisA