I could never have pulled this off in such a short time without Jacques Distler
more or less on constant stand-by (thanks Jacques!). Looking at the
times his emails were send I have no idea in which time zone he lives
(let alone sleeps…). So, here a walk-through the changes :

As
I’m on WP 2.0.5 I’ll start with Frederick’ post. He tells me I have to install first the itex2MML binary as
explained by
Jacques but I find that there is more recent
material and therefore download the most recent imath2MML-package
and follow the readme. There is a Mac OSX binary but it’s not clear
for what processor (PPC/Intel/Binary) but a quick mail to Jacques learns
me that it’s PPC which is fine by me but on the spot he puts a
universal binary online, so whatever your Mac is you can just download
the binary, copy it to /usr/local/bin and make sure its chmodded
755.

Back to Frederick’s post, download and install the plugin itexToMML.php in the usual way
(fortunately I spot just in time that I have to change one line saying
where my itex2MML binary is (in Frederick’s file it is NOT the default
location)). You can verify whether the plugin and itex2MML do what they
are supposed to do by typing a LaTeX-command in a post and save it. The
output will not produce the desired formula but have a look at the
source file and see whether there is some mathML code in it. If so,
fine! If not, go back and check everything.

If this works, it is
“merely” a problem of getting your mathML served. Frederick suggests
to unpack wordpress_mathML.zip in the wp-includes directory (but you
better make sure you have made a copy of the original class.php and
functions-formatting.php files. In the end I decided against this
approach (that is, to replace only the functions-formatting.php but NOT
the class.php file). If you have two or more themes you want to
maintain, it is probably better to change the headers (because this is
what we have to do to get mathML served) only in those themes which are
XML-sound. In my case, the Command Line Interface theme most certainly is NOT!!!).

Go to your
theme-files and look for the header.php (or similar) file and replace
the default header by the code in the addendum to
this post within php-tags. If you can go to your blog-page then you
are in good shape and things should work well (apart possibly from
layout considerations, see below). Of course, in my case i was greeted
by ” XML “yellow screen of death” (as Jacques calls
it) and I was convinced I did something wrong, so I tried out several
useless things for a couple of hours before it dawned on me that the
reason might just be that my blog-files were not valid XHTML (and the
new headers are very demanding on serving only well-form XHTML). I had
to modify all changes I made to sidebars etc. as well as rewrite parts
of my first posts (I used to take a rather liberal view on writing
blog-posts, writing a mixture between Markdown and improvised HTML and
in the process was very lax about closing IMG-tags and the likes).
But after some time and numerous corrections to the files I got the
main-page up and running (and even had the mathML served as a readable
formula) apart from the fact that I barely recognized my own site.

I printed out source files of the page with and without changed
headers and couldn’t find a difference. So, it had to do with the
CSS-style files, but why on earth would the new headers be picky about
CSS? But as a last resort, after narrowing the search down to one
CSS-line, I asked Jacques whether he had an idea what went on. His reply
will be remembered for quite some time :

A fascinating
question. The answer is that it *is* following the CSS directive, but
in XHTML, ‘body’ is not what you think it is. ‘body’ is just big enough
to contain its content. It does not fill the viewport. ‘html’ fills the
viewport. The solution (a solution) is described in
http://golem.ph.utexas.edu/~distler/blog/archives/000203.html

Many hours later, I still haven’t got a clue what
this is all about, but I blindly followed the hint and surely all
problems vanished. In short, another day wasted in front of a
computer-screen.

At the moment I’m back to old headers and
will not be writing mathML for some time as I have the vast job ahead to
validate all my previous posts to XHTML-standards (if not you would see
more yellows screens of death than anything else. So, here’s the
strategy I’ll be taking in the weeks ahead (I’ll sleep on it tonight
so if any of you think there is a better way, reply quickly)

• rewrite each and every post in proper MultiMarkdown using iTeX for
  the most common math and only resorting to LaTeXRender for exotic things
  (such as Sudoku, Chess, Dvonn) and run these posts through Markdown
  (to get basic HTML and all links in place).
• download these
  files to the WP-database (so that in the CLI-interface you will be able
  to follow all links, but will read all iTeX as TeX-commands (as the
  command line intended after all).
• in the process change all
  broken links to the default permalink-structure (with index.php?p=231 or
  so).

Clearly, this is a work that will take a couple of
weeks but it may be fun to reread these old posts and possibly add new
information about the subjects. When I’m making these changes, I’ll
use the new headers so if you are using a smart browser look out for the
yellow screens. When they happen, either use a dumb browser (such as
Safari) or go into CLI-interface mode where everything should still
work. I plan to start with the oldest posts as this seems more fun to
me.

Needless to say I couldn’t resist installing the
Wordpress CLI-theme the moment I spotted it! A command line
interface to your blog! awesome! If you want to have a go at the
original version, take a look at Rod McFarland’s blog.
Just type ‘ls’ to the prompt and you’ll be hooked. Or you can have a
look at the command line interface of NeverEndingBooks by going to the
left sidebar and clicking CLI under the ‘Command Line Version’ header
(don’t be afraid you can always come back by clicking on the
GUI-interface over there). My design is black on a light-gray background
and is no where near as cool as the original theme but it was the only
quick way around some limitations of the CLI-theme.

The
CLI-theme operates as a front-end via a small interpreter which draws
the information directly from the WordPress-database. As a result you
loose the effect of all post-processing by plugins such as Markdown and LatexRender two of
the plugins I use most! I could still live with the idea that pure LaTeX
was served to a CLI-environment between tex-tags, but surely I didn’t
want to loose all my links! The quick (and extremely dirty) way around
it was to resubmit the relevant part of the HTML-source files of the
GUI-frontend posts to the WP-database. And to serve the same LaTeX-gifs
to the GUI and CLI interface I needed the backgound to be rather light
gray (taking #BDBDBD gray would have been much nicer wrt. the cool
rasterized grayed-images but then some of the more recent LaTeX-gifs
became partially unreadable). Oh, and in the process I had to update the
permalink structure, thereby wrecking allmost all internal
reference-links (but I’ll sort them out soon, I promise).

So, a
lot of work for a rather meagre result. What do I like about the
CLI-interface (apart from old time nostalgia)? I really like the
searching facility. Just type ‘search yourword’ to the prompt and it
will give you all posts containing that word (much quicker than in the
GUI-interface) and if you remember at least one word from a post-title,
feeding it to the prompt will give you the entire post (or a list of
posts if the same word appears in different posts). Try out typing
‘Perelman’ to see what I mean. Besides, bots don’t seem to know what to
do with the CLI-interface so for the few days I had this theme as my
default theme I was alone on NeverEndingBooks mast of the time (which
helped a lot having to change that many posts). So, whenever I want to
have the site to myself I’ll just change the default theme from now
on.

Still, I did put back the old GUI as default because the
CLI-theme still has a few drawbacks. Such as, it is impossible to write
a sizable comment (not that too many of you do this, but anyway) and
some other quirks. Still Rod McFarland is working on a version 2 (and
even set up a google-group for
those who want to code along, and maybe I’ll join the effort) which
promises a great improvement and I’m rather confident that by version
3.14 it will be in a state that I’ll have the CLI-interface as my
default. Until then, I’ll keep up the two front-ends and allow you to
toggle as you like (your browser will remember your preference).

I realize most of you are youngsters and not of my cpu2
generation so have a hard time imagining how exiting a command line
prompt is. Fortunately, Neal Stephenson has made the full text of “In
the beginning ! was the command line” available as a
free download. Print it out and enjoy!

An example : it took me a day to figure out why
this page said there was just 1 visitor online whereas log files showed
otherwise. The PHP-script I used checked this by looking at the
IP-address via _REMOTE_ADDR_ which is perfectly OK on an ordinary
Mac OS 10.3 machine, but _not_ on an OS X-Server! For some reason
it gives as the REMOTE_ADDR just the IP address of the Server (that
is, lievenlb.local in this case) so whoever came by this page got
tagged as 143.129.75.209 and so the script thought there was just one
person around… The trivial way around it is changing every
occurence of REMOTE_ADDR by _HTTP_PC_REMOTE_ADDR_.
Easy enough but it took me a while to figure it out.

Another
example : over the week-end this weblog got a stalker! There were over
100 hits from 38.113.198.9, so whoever that is really liked this site
but didn't have time to read a thing… Again, the standard
solution is to ban the IP-address and most weblog-packages have such a
tool on their admin-page. But whathever I tried and Googled WordPress doesn't seem to have it
on board. There were a few hacks and plugins around claiming to do
something about it but none of them worked! So, I tried more drastic
actions such as editing .htaccess files which I thought would solve
everything (again, no problem under 10.3 but _not_ under
10.3-Server!). Once more, a couple of hours lost trying to figure out
how to get the firewall of a Mac-Server do what I needed. The upshot is
that I know now all dark secrets of the _ipfw_ command, so no
more stalking around this site…

In the process of
grounding my stalker, I decided that I needed better site-stats than my
homemade log-file provided. Fortunetely, this time I picked a package
that worked without too much hassle (one more time I had to make the
REMOTE_ADDR substitution but apart from that all went well). You will
see not too much of the power of this stats-package on the page (apart
from the global counter), I feel that such things are best forgotten
until something strange occurs (like stalkers, spammers and other
weirdos). A nice side-effect though was that for the first time I had a
look at _referring pages_, that is the URL leading to this weblog.
Lots of Google searches (some strange ones) but today there were also a
number of referrals from a Chinese blog. I checked it out and it turned
out to be the brand new Math is Math! Life is Life! weblog…

Another time
consuming thing was getting the BBC-news RSS feeds working in the
sidebar, so that you still get _some_ feel for reality while
being trapped here. I am not yet satisfied with the layout under
Explorer, but then everyone should move on to Safari (so I did give up
trying to work out the PHP-script).

But most time I wasted on
something that so far has left no trace whatsoever here. A plugin that
allows specific posts to be read only by registered users (of a certain
'level', that is WordPress can give users a level from 0 to 10
with specific degrees of freedom). But clearly at the same time I wanted
the rest of the world to have at least some indication of what they were
missing (such as a title with a nice padlock next to it) but so far I
didn't get it working. The only trace of a closed posting would be
in the sidebar-listing of the ten last posts but gives an error message
when an unauthorized user clicks on it. So, still a lot of
headache-sensitive work left to do, but it is about time to get back to
mathematics…

update (febr. 2007) : the
padlock-idea is abandoned.

cd /usr/local sudo tar -pxf
/Users/lieven/Desktop/Singular-2-0-4-ppcMac-darwin.tar sudo tar -pxf
/Users/lieven/Desktop/Singular-2-0-4-share.tar

Then
follow the instructions making the symbolic links and you have Singular
working. The next step is to go to the GAP Packages page and go to the
package Singular for full documentation.
To use Singular in a GAP-session, here is an example

gap>
LoadPackage("singular");
The GAP interface to Singular
true
gap> StartSingular();
I  Started Singular (version 2004)
gap> SetInfoLevel( InfoSingular, 2 );
gap> G:= SymmetricGroup( 3 );;
gap> R:= PolynomialRing( GF(2), 3 );;
gap> GeneratorsOfInvariantRing( R, G );
[ x_1 x_2 x_3, x_1*x_2 x_1*x_3 x_2*x_3, x_1*x_2*x_3 ]
gap> I:= Ideal( R, last );;
gap>GroebnerBasis( I );
I  running GroebnerBasis... I  done
GroebnerBasis. [ x_1 x_2 x_3, x_2^2 x_2*x_3 x_3^2, x_3^3 ]
gap>