From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Xue Fuqiao Newsgroups: gmane.emacs.help Subject: About Circular Objects Date: Tue, 25 Dec 2012 16:52:49 +0800 Organization: The Church of Emacs Message-ID: <20121225165249.e5822f6cc71fa88d959efcd0@gmail.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1356446632 21181 80.91.229.3 (25 Dec 2012 14:43:52 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 25 Dec 2012 14:43:52 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Tue Dec 25 15:44:08 2012 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1TnVjj-0000ek-Sx for geh-help-gnu-emacs@m.gmane.org; Tue, 25 Dec 2012 15:44:08 +0100 Original-Received: from localhost ([::1]:36706 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TnVjV-0006qi-Ni for geh-help-gnu-emacs@m.gmane.org; Tue, 25 Dec 2012 09:43:53 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:41139) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TnQFy-0006uv-MZ for help-gnu-emacs@gnu.org; Tue, 25 Dec 2012 03:53:03 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TnQFx-0003Jq-P8 for help-gnu-emacs@gnu.org; Tue, 25 Dec 2012 03:53:02 -0500 Original-Received: from mail-pa0-f54.google.com ([209.85.220.54]:60057) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TnQFx-0003Jl-Ie for help-gnu-emacs@gnu.org; Tue, 25 Dec 2012 03:53:01 -0500 Original-Received: by mail-pa0-f54.google.com with SMTP id bi5so4455016pad.41 for ; Tue, 25 Dec 2012 00:53:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:date:from:to:subject:message-id:organization:x-mailer :mime-version:content-type:content-transfer-encoding; bh=mRFy3PV5BoBfl4AezSE4/N8cf/Dgsh0R7MvuXnmQoto=; b=DaWyi01+YIq3MGo7IwZ0FqxLm5vYDsUN9Jfr5HrIPzhtEf2Q34YY+F6j28PXEnuqgs DgbysPKQp2RtJY9tsFBtVzYT8mIhomtMuYN8fNot52rVWll7G4eLYAGZQHKPpxoIseYA r68uu2Jn2y+usC8VpolbS6aFJVUMsaaJ+II5RK582LjqeBivo+aNRl/DZMItF1Jaihlz pXVD0uswyHPxUCtr4h69tQXdxMlwapkW/+NiqeA/lW6OfHj21U0/zA8HU8DEox3puv6W t45iPHK63oQoleRpAP8C0Agy+YL6LksIpjKZUyiYkv1cdppMu1yLA2q9IAvKVtpOVV4r INxw== X-Received: by 10.68.234.201 with SMTP id ug9mr75009364pbc.63.1356425580532; Tue, 25 Dec 2012 00:53:00 -0800 (PST) Original-Received: from Emacs ([61.148.242.122]) by mx.google.com with ESMTPS id a4sm14327225pax.25.2012.12.25.00.52.57 (version=SSLv3 cipher=OTHER); Tue, 25 Dec 2012 00:52:59 -0800 (PST) X-Mailer: Sylpheed 3.2.0 (GTK+ 2.24.13; x86_64-pc-linux-gnu) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 209.85.220.54 X-Mailman-Approved-At: Tue, 25 Dec 2012 09:43:49 -0500 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:88313 Archived-At: I have a question about the #N# read syntax and #N= syntax. Look at this code: (progn (setq x '#1=(a #1#)) (eq x (cdr x))) Why does this code return nil? Isn't the second element the list itself? -- Best regards.