Path: news.cambrium.nl!textnews.cambrium.nl!feeder2.cambriumusenet.nl!feed.tweaknews.nl!209.197.12.242.MISMATCH!nx01.iad01.newshosting.com!newshosting.com!198.186.194.249.MISMATCH!transit3.readnews.com!news-out.readnews.com!news-xxxfer.readnews.com!postnews.google.com!p36g2000prn.googlegroups.com!not-for-mail From: David BL Newsgroups: comp.databases.theory Subject: Re: Using the RM for ADTs Date: Fri, 24 Jul 2009 16:15:00 -0700 (PDT) Organization: http://groups.google.com Lines: 15 Message-ID: <09bad9a9-ce5c-41d6-9262-1482bf554ab9@p36g2000prn.googlegroups.com> References: <2fb127c0-13e3-45e6-a93b-3afe7dead964@d4g2000yqa.googlegroups.com> <4a5bbaad$0$18772$703f8584@news.kpn.nl> <66836607-5ab8-482e-a36c-fa890e7cd57d@d9g2000prh.googlegroups.com> <4a6a2dda$0$8612$703f8584@news.kpn.nl> NNTP-Posting-Host: 203.59.253.107 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1248477300 18659 127.0.0.1 (24 Jul 2009 23:15:00 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Fri, 24 Jul 2009 23:15:00 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: p36g2000prn.googlegroups.com; posting-host=203.59.253.107; posting-account=NLRoXAoAAAC7VxPeAzHGCGNn85XdBOyR User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 2.0.50727),gzip(gfe),gzip(gfe) Xref: news.cambrium.nl On Jul 25, 5:55 am, rp@raampje.(none) (Reinier Post) wrote: > David BL wrote: > > [...] > > >I would like to confirm my understanding here: FOL restricts > >quantification to be over elements in the domain of discourse, whereas > >SOL also allows for quantification over sets. In particular testing > >for existence of an isomorphism is quantification over a set because a > >function is basically a set of pairs. > > I'm not aware that SQL allows anything like this. > Can you give me an example? SOL = second order logic