Path: news.cambrium.nl!textnews.cambrium.nl!feeder1.cambriumusenet.nl!feed.tweaknews.nl!195.208.113.2.MISMATCH!goblin2!goblin3!goblin.stu.neva.ru!tioat.net!not-for-mail From: paul c Newsgroups: comp.databases.theory Subject: Re: relative complement? Date: Mon, 04 Apr 2011 07:22:32 -0700 Lines: 16 Message-ID: <201104041422.UTC.inck7c$jcb$1@tioat.net> References: <201102231630.UTC.ik3cmc$qmj$1@tioat.net> <5ebcafc7-51fe-4b40-a57b-36b76c06ee8c@x11g2000yqc.googlegroups.com> <201103181441.UTC.ilvquh$uce$1@tioat.net> <7b387bd7-a777-4c6f-b337-ae8faa03e34c@d28g2000yqf.googlegroups.com> <201103182144.UTC.im0jo4$5fa$1@tioat.net> <53f2155d-1f47-43ac-a26b-d7dfe02515f3@w7g2000yqe.googlegroups.com> <201103190030.UTC.im0tg1$825$1@tioat.net> <201103282149.UTC.imqvpb$vj1$1@tioat.net> <0197e33f-e108-4a40-8f7d-1569e6569646@y26g2000yqd.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Mon, 4 Apr 2011 14:22:36 +0000 (UTC) Injection-Info: tioat.net; posting-host="a044a530a88f792cff1a0217681a8b76"; mail-complaints-to="news_AT_tioat_DOT_net" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 In-Reply-To: <0197e33f-e108-4a40-8f7d-1569e6569646@y26g2000yqd.googlegroups.com> Xref: news.cambrium.nl On 02/04/2011 8:49 AM, Erwin wrote: > On 28 mrt, 23:49, paul c wrote: ... > The "functional" quality of a "functional" program is that it "does > nothing else but generate a result". Note that I used the word > "generate" and _NOT_ the word "record" !!! A functional program can > "generate" the number three as a result, and that's it. You can look > at it, and note that the result is the number three, but _AS SOON AS > YOU DO ANYTHING TO ACTUALLY RECORD_ that result (such as assigning it > to some portion of the value of a DBVAR), you are outside the realm of > "true" functional programming !!! Yes, I'd say that's accurate, but I don't see why it should be considered significant. It's 'outside the realm' of relational algebra too. What I'd say should be significant is whether contradictions are possible regardless of how the recording is accomplished.