From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Evans Winner Newsgroups: gmane.emacs.help Subject: Re: canonical name ending "-p" Date: Fri, 18 Mar 2011 14:36:08 -0600 Organization: Aioe.org NNTP Server Message-ID: <87vczgp3nr.fsf@gmail.com> References: NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1300480843 5465 80.91.229.12 (18 Mar 2011 20:40:43 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 18 Mar 2011 20:40:43 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Mar 18 21:40:39 2011 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Q0gTO-0007ny-Dy for geh-help-gnu-emacs@m.gmane.org; Fri, 18 Mar 2011 21:40:38 +0100 Original-Received: from localhost ([127.0.0.1]:55052 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q0gTO-0006Jr-25 for geh-help-gnu-emacs@m.gmane.org; Fri, 18 Mar 2011 16:40:38 -0400 Original-Path: usenet.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!newsgate.cistron.nl!newsgate.news.xs4all.nl!news2.euro.net!feeder.news-service.com!94.75.214.39.MISMATCH!aioe.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 23 Original-NNTP-Posting-Host: 4xmhsRr5Aeb6D0t2Thq8sQ.user.speranza.aioe.org Original-X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.50 (gnu/linux) X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:qJWA80FJmDK6Qf8tvZAD5NbbjTk= Original-Xref: usenet.stanford.edu gnu.emacs.help:186102 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:80244 Archived-At: ,------ ken wrote ------ | Lots of things in elisp end in "-p"... is there some | particular meaning in this? On a related note (since Pascal already explained it) I have wondered why the rather odd use of the term "predicate" was chosen. When I hear the term "predicate" I usually think of its meaning in grammar and logic. But there is also the use in which one says that if one thing (A) depends on another thing (B) that A is "predicated on B." I suspect it is because one might verbally reason that in: (if (atom t) t nil) the answer to whether Lisp will return t or nil is predicated on the results of (atom t), therefore by extension we call the function itself a predicate. It's a little confusing because it is not one of the common uses of the noun "predicate." I would be interested to hear from someone who knows if this is indeed the sense on which the term was chosen.