Received: by nummer-3.proteosys id <01C19443.4C9DA6AC@nummer-3.proteosys>; Thu, 3 Jan 2002 11:42:11 +0100 Return-Path: <@vm.gmd.de:LATEX-L@DHDURZ1.BITNET> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C19443.4C9DA6AC" x-vm-v5-data: ([nil nil nil nil nil nil nil nil nil][nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil]) X-MimeOLE: Produced By Microsoft Exchange V6.5 x-to: LATEX-L%DHDURZ1.BITNET@uga.cc.uga.edu Content-class: urn:content-classes:message Subject: Re: indented material Date: Thu, 31 Oct 1991 20:44:22 +0100 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: From: "Michael Downes" Sender: "LaTeX-L Mailing list" To: "Rainer M. Schoepf" Reply-To: "LaTeX-L Mailing list" Status: R X-Status: X-Keywords: X-UID: 440 This is a multi-part message in MIME format. ------_=_NextPart_001_01C19443.4C9DA6AC Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable (About \leftskip vs. \parshape in list environments) Victor wrote: > I must admit I was wrong here. The \list command contains the line > \parshape 1 \@totalleftmargin \linewidth > but I don't see how this parshape is automatically applied > to paragraphs that start inside an item. Chris? In the list environments \par is also defined to be {\@@par}; ending the paragraph inside a group means that \parshape is not reset to 0 globally, hence the prevailing \parshape will continue for the next paragraph. > >> However, there is an important difference: in the first case the = \hsize > >> is decreased by the amount of the indentation; inthe second case = the > >> \hsize stays the same. > >In neither case is the \hsize changed. > > Hm. It appears that the \hsize is only decreased when the > paragraph is finally broken into lines, not while it's being > composed. Makes sense, but then the problem still stands. It would perhaps be more accurate to say that TeX uses the line width specified by \parshape instead of \hsize for breaking the paragraph, with the value of \hsize remaining unchanged throughout as Chris said. > What were the reasons of the original implementor of LaTeX > to do things this way, instead of using \leftskip? I believe the primary difference is that the values of \displaywidth and \displayindent inside of a display are taken from \parshape, whereas \leftskip is not taken into account at all by a display when positioning the equation material. Practically speaking, this means that in a list environment a displayed equation will be centered within the line width of the list, rather than \columnwidth. It's not clear to me that this is always desirable, but a problem that sometimes comes up in AMS journal production is for an author to put a displayed equation in the abstract and label it with an equation `number' such as `(*)'. The number appears outside the bounding box of the abstract, which is indented on both sides, because the indention is implemented in AMSTeX with \leftskip\rightskip rather than with \parshape. Michael Downes mjd@math.ams.com (Internet) ------- ------_=_NextPart_001_01C19443.4C9DA6AC Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: indented material

(About \leftskip vs. \parshape in list environments) = Victor wrote:

> I must admit I was wrong here. The \list command = contains the line
>      \parshape 1 = \@totalleftmargin \linewidth
> but I don't see how this parshape is = automatically applied
> to paragraphs that start inside an item. = Chris?

In the list environments \par is also defined to be = {\@@par}; ending
the paragraph inside a group means that \parshape is = not reset to 0
globally, hence the prevailing \parshape will = continue for the next
paragraph.

> >> However, there is an important = difference: in the first case the \hsize
> >> is decreased by the amount of the = indentation; inthe second case the
> >> \hsize stays the same.
> >In neither case is the \hsize = changed.
>
> Hm. It appears that the \hsize is only decreased = when the
> paragraph is finally broken into lines, not = while it's being
> composed. Makes sense, but then the problem = still stands.

It would perhaps be more accurate to say that TeX uses = the line width
specified by \parshape instead of \hsize for breaking = the paragraph,
with the value of \hsize remaining unchanged = throughout as Chris said.

> What were the reasons of the original implementor = of LaTeX
> to do things this way, instead of using = \leftskip?

I believe the primary difference is that the values of = \displaywidth
and \displayindent inside of a display are taken from = \parshape,
whereas \leftskip is not taken into account at all by = a display when
positioning the equation material. Practically = speaking, this means
that in a list environment a displayed equation will = be centered
within the line width of the list, rather than = \columnwidth. It's not
clear to me that this is always desirable, but a = problem that
sometimes comes up in AMS journal production is for = an author to put a
displayed equation in the abstract and label it with = an equation
`number' such as `(*)'. The number appears outside = the bounding box of
the abstract, which is indented on both sides, = because the indention
is implemented in AMSTeX with \leftskip\rightskip = rather than with
\parshape.

Michael Downes      = mjd@math.ams.com (Internet)
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