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diff --git a/macros/generic/diagrams/taylor/msg1992.html b/macros/generic/diagrams/taylor/msg1992.html new file mode 100644 index 0000000000..14158b7260 --- /dev/null +++ b/macros/generic/diagrams/taylor/msg1992.html @@ -0,0 +1,236 @@ + + + + + + + + +<title> Commutative Diagrams in TeX</title> + +<h1 align="center">Commutative Diagrams in TeX </h1> + +<h3 align="center">Paul Taylor </h3> + +<h3 align="center">September 1992 </h3> + + + + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + +<div class="p"><!----></div> + + +<div class="p"><!----></div> + + + + + + +<div class="p"><!----></div> + +<div class="p"><!----></div> + + + +<div class="p"><!----></div> + + + +<div class="p"><!----></div> + + +<div class="p"><!----></div> + + + +<div class="p"><!----></div> + + + + + + +<div class="p"><!----></div> + + +<div class="p"><!----></div> + + +<h2>Message sent to registered users in September 1992</h2> + +<div class="p"><!----></div> +This message brings news of the development of my <span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> package for +drawing "commutative" diagrams, which is now widely used in the +category theory and theoretical computer science communities. It is +being sent directly to all of the users I know of (who have requested +it by electronic mail or FTP from me, or asked questions about it), +but as I know the package has been passed on, I would be grateful if +you would <em>copy this message to anyone to whom you have given + the package itself.</em> + +<div class="p"><!----></div> +The package was originally advertised on the "types" and +"categories" electronic mailing lists in July 1990. In the following +eighteen months some fixing of bugs took place, but there was little +substantial change. + +<div class="p"><!----></div> +Since April 1992, I have re-written most of the code, largely with a +view to improving the geometrical layout of the diagrams. Before +completing this work and calling it version 4, I would like some +feedback from users. + +<div class="p"><!----></div> +One of the areas which I have neglected in the past (largely because +<span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> makes it so difficult) is diagonal arrows. The code for drawing +these using <span class="roman">L</span><sup><span class="roman">A</span></sup><span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> line segments has been re-written: now the closest +available slope is chosen automatically and the commands have names +similar to the horizontals and verticals. + +<div class="p"><!----></div> +However to do a better job of diagonals (and in future to support +curved lines) some extension to <span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> is needed. Being extensions they +are necessarily not standard. Three possibilities are: + +<ul> +<li> additional fonts (as, for example, used by Spivak's Lamstex). + However my experience of design-size fonts and linear logic symbols + suggests that for users without expert knowledge or control of their + local <span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> systems this is more trouble than it's worth. +<div class="p"><!----></div> +</li> + +<li> PostScript is, I believe, now almost universally used as the + language in which <span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> documents are sent to a printer. PS commands + can be embedded in DVI files and incorporated in the PS translation + without extra system or user files or any user intervention. This is + to some extent dependent on which DVI<font face="symbol">®</font +>PS translator is used. In + the new version this is exploited in an option to implement + diagonals by rotating horizontals, which works with Tomas Rokicki's + "dvips". +<div class="p"><!----></div> +</li> + +<li> TPIC is a graphics extension of <span class="roman">T</span><sub><span class="roman">E</span></sub><span class="roman">X</span> which uses a simpler set + of embedded commands. These can be used to draw diagonal lines and + curves but not to perform rotations; they are, however, understood + by Vojta's "xdvi" as well. Another option in the new version uses + these to draw diagonal lines. +<div class="p"><!----></div> +</li> +</ul> +Besides diagonals, the code for adjusting horizontal and vertical +arrows has been completely rewritten and does a much better job of the +geometry. Many of the problems with alignment, positioning and gaps +have been fixed automatically, and greater control is given to the +user to adjust those which cannot be. There are also several new +options for the placement of the finished diagram on the page. + +<div class="p"><!----></div> +Arrow commands are now declared in a much simpler way. The declaration + +<pre> + \newarrow{CrossedInto}{hook}-+-> + +</pre> +is now all that is needed to define the example <tt>\rCrossedInto</tt> +in the manual, along with the corresponding left, down, up and +diagonal commands. Another option makes a consistent selection of +arrowheads for all arrows, from a choice of vee, LaTeX, curlyvee, +triangle and blacktriangle. + +<div class="p"><!----></div> +So much for selling you the new version. The reason for mailing you +and asking for comments before completing what I intend to do for +version 4 is that I want to get feedback on the following questions: + +<div class="p"><!----></div> + +<ul> +<li> Can you use FTP (file transfer protocol)? This is the easiest + method of distribution for me and for you, and there is now a huge + volume of public domain software available by this method. My + archive is called <tt>ftp.dcs.qmw.ac.uk</tt> + and the diagrams package is in the directory /pub/tex/contrib/pt/diagrams. + Please try to fetch the new version and manual by this method. +<div class="p"><!----></div> +</li> + +<li> If you can't use FTP, and your electronic mail passes via + non-ASCII machines (particularly BITNET), what characters tend to + get corrupted? The new version uses a restricted character set to + avoid this problem. +<div class="p"><!----></div> +</li> + +<li> Do you have available for printing final copy a printer which + understands Adobe PostScript, for example an Apple or Sun + laserwriter? Who is the author of the DVI-> PS translation program + you use? Please fetch the new version, try the PostScript option and + tell me if you have any difficulty printing. (You may have to change + the <tt>\verbatim@ps@special</tt> macro if you don't use Rokicki's + dvips: if so, please send me details.) You can preview with a PS + previewer such as PageView under OpenWindows or + GhostView/GhostScript under Xwindows. +<div class="p"><!----></div> +</li> + +<li> Do your DVI translators and previewers understand TPIC + <tt>\special</tt>s (as used in eepic.sty)? Please try the TPIC + option. I would like to know whether it is worth putting effort into + PostScript, TPIC or some other method. +<div class="p"><!----></div> +</li> + +<li> Have you defined your own arrow commands using + <tt>\HorizontalMap</tt>, <tt>\VerticalMap</tt> or <tt>\DiagonalMap</tt>? + Please use "grep alMap *.tex *.sty" or some similar command to + find out, and tell me if you have used any components other than + those in the source of version 3. It is in your interests to do + this, because <tt>\newarrow</tt> defines arrow commands in a + different way. +<div class="p"><!----></div> +</li> + +<li> Please tell me if you have any difficulty adapting to the new + version, or any general comments about doing so which might be of + benefit to other users. +<div class="p"><!----></div> +</li> + +<li> Other comments: have you used other packages for drawing + diagrams? Do you have applications for my package other than the + categorical diagrams for which it was designed? What do you see as + the major limitations of the package? What persuaded you to use it, + or not to use it? +<div class="p"><!----></div> +</li> +</ul> + +<div class="p"><!----></div> |