Almost all of TeX's mathematics is supported with the exception of a few obscure symbols that are absent from the fonts normally available to browsers. Support includes, for example, in-line equations with subscripts and superscripts, display equations with built-up fractions, over accents, large delimiters, operators with limits; matrix, pmatrix, cases, [but not bordermatrix]; over/underbrace [but using a rule, not a brace].
Font styles: it, bf, sl, uppercase, accented characters written like \"o or \'{e}. Guess the intent of font definitions [optionally, remove contruct].
Macro definitions: def, edef, xdef, but all definitions are global. Definitions with delimited arguments1. Input of files [but not from the implicit texinputs path, see 5.4]. Newcount, number, advance and counter setting.
Centerline, beginsection, item, itemitem, obeylines; hang, hangindent, narrower [for entire paragraphs, hangafter ignored]. Headline is made into a title, footnote{}{}. Comments: removed.
Tables: halign [uses border style if the template contains vrule]. Settabs, \+.
These cover most of the vital LaTeX constructs. Internal hypertext cross-references are automatically generated (e.g. by ref and tableofcontents) provided LaTeX has previously been run on the document and the appropriate command-line switch is used.
\epsfbox{file.[e]ps} Puts in an anchor called "Figure" linked to
file.[e]ps (default), or alternatively calls user-supplied script
to convert the [e]ps file to a gif image and optionally inline it.
\special{html:"tags"} inserts ``tags'' into the HTML e.g. for images etc.
\href{reference}{anchor} highlights ``anchor'' with href=``reference''.
\begin{[raw]html} ... \end{[raw]html} environment passed direct to output.
\tthdump{...} The group is omitted by TtH. Define \tthdump as a nop for TeX.
%%tth:... The rest of the comment line is passed to TtH (not TeX) for parsing.
When TtH encounters TeX constructs that it cannot handle either because there is no HTML equivalent, or because it is not clever enough, it tries to remove the mess they would otherwise cause in the HTML code, generally giving a warning of the action if it is not sure what it is doing. The following are examples of constructs not translated.
\magnification \magstep etc : Removes the whole construct. Any dimension and glue commands: removed. All conditionals (if else fi etc) except ifmmode: removed/ignored. Boxes: usually ignored (but this can sometimes cause problems).
The source for TtH is flex code which is processed to produce a C program tth.c which comprises the distribution. This file is compiled by
gcc -o tth tth.c
or whatever C compiler you are using. Compilation takes a couple of minutes on a fast 486. Alternatively, you may be able to obtain a precompiled executable from wherever you accessed this file.
The executable should then be copied to whatever directory you want (preferably on your path of course). That's all!
Command line (switches can appear anywhere on the line):
tth [switches -c -d ... ] <file.tex [>file.html] [2>err]
-a automatic picture environment conversion using latex2gif (default omit).
-c prefix header "Content-type: text/HTML" (for direct web serving).
-d disable delimited definitions.
-e? epsfbox handling: -e1 convert figure to gif using user-supplied ps2gif.
-e2 convert and include inline. -e0 (default) no conversion, just ref.
-f? sets the depth of grouping to which fractions are constructed built-up
f5 (default) allows five levels built-up, f0 none, f9 lots.
-g don't guess an HTML equivalent for font definitions, just remove.
-h print help. -? print usage.
-i use italic as default math font.
-Lfile tells tth the base file (no extension) for LaTeX auxiliary input,
enables LaTeX commands (e.g. \frac) without a \documentclass line.
-n number eqnarray environments just once (default number each line).
-pdirectory designate an additional directory to search for input files.
-r output raw HTML (no preamble or postlude) for inclusion in other HTML.
-t display built-up items in textstyle equations (default in-line).
-xmakeindx specify a non-standard makeindex command line.
-v give verbose commentary.
The program is a filter, i.e. it reads from stdin and writes to stdout. In addition, diagnostic messages concerning its detection of unknown or untranslated constructs are sent to stderr.
TtH is extremely fast in default mode on any reasonable hardware. Conversion of even large TeX files should be a matter of a second or two. This makes it possible to use TtH in a CGI script to output HTML directly from TeX source if desired; (stderr may then need to be redirected.)
Equations are translated internally into HTML3.2 as much as it allows. TtH uses HTML3.2 tables for layout of built-up fractions in display equations. It also uses the extension HTML tag < font face=``symbol'' > , supported by Netscape and other major browsers (and part of the HTML4.0 specification) to render Greek and large delimiters etc. Untranslatable TeX math tokens are inserted verbatim.
The internal approach to equation translation is a major area where TtH departs from the philosophy of Latex2html and its derivatives. TtH does not use any images to try to represent hard-to-translate constructs like equations. Instead it uses the native ability of HTML to the fullest in providing a semantically correct rendering of the equation. The aesthetic qualities obtained are in practice no worse on average than Latex2html's inlined images, which are generally slightly misaligned and of uncertain scaling relative to the text. Some limitations in the HTML code are inevitable, of course, but one ends up with a compact representation that can be rendered directly by the browser without the visitor having to download any additional helper code (e.g. Java equation renderer).
TtH offers an option [-i] which makes italic the default font within equations, and thus the style more TeX-like. The italic font appearance in browsers is not as satisfactory as TeX's math italic, so for many documents roman looks better.
Spacing in equations is handled slightly differently by TtH than by TeX. The reason is that most browsers use fonts that will crowd the characters horizontally too close for comfort in many cases (for example: M||/2). Also, built-up HTML equations are more spread out vertically than in TeX. Therefore TtH equations look better if spaces are added between some characters. So TtH does not remove spaces in the original TeX file between characters in equations. The author is thus able to control this detail of layout in the HTML without messing up their TeX file - since TeX will ignore any spaces inserted. Legacy TeX code that contains a lot of spurious whitespace (ignored by TeX) may, as a result, occasionally become too spread-out when translated.
Forward references in LaTeX are handled by multiple passes that write auxiliary files. TtH does only a single pass through the source. If you want TtH to use LaTeX constructs (e.g. tableofcontents, bibliographic commands, etc.) that depend on auxiliary files, then you do need to run LaTeX on the code so that these files are generated. You must also tell TtH, using the switch -Lfilename, the base file name of these auxiliary files (which is the name of the original file omitting the extension). If TtH cannot find the relevant auxiliary file because you didn't run LaTeX and generate the files or didn't include the switch, then it will omit the construct and warn you. Forward references via ref will not work if the .aux file is unavailable, but backward references will.
If you routinely use LaTeX in a way that requires auxiliary files and grow tired of always having to specify the -L switch to TtH, a simple ``l2h'' script may be useful. For example under Linux (Un*x) a script such as
tth <$1.tex >$1.html -L$1or the equivalent batch file under DOS/Wind*ws, may save some typing.
When processing a LaTeX file that contains the \makeindex command in its preamble, TtH will construct an appropriately cross-hyperlinked index that will be input when the command \printindex is encountered, which must be after all the index references \index{ ... } in the document. TtH does this independently of LaTeX, but not of the subsidiary program makeindex that is normally used with LaTeX to produce the final index ``file.ind''. TtH creates its index entries in a file with extension .tid (Tth InDex). Because of makeindex program limitations, TtH currently removes all the page-number formatting that is present in the index entry (but not the reference formatting). It also uses the section reference style ``1-2'', separated by a dash, because this is the standard form that makeindex expects and it is cumbersome to change it. The actual reference is less important to the reader than the fact that TtH inserts a link to the actual place in the document indexed. When the \printindex command is encountered, TtH closes this file and runs makeindex on it, which creates by default a file with extension .ind, and then TtH reads the .ind file in as its index. Because the .ind file that TtH produces may well be incompatible with running LaTeX itself on the file, TtH deletes the .ind file that it creates (and hence one is left without such a file at the end). If, instead of creating an index file during TtH processing, one wants to use with TtH an index file already created, all that is needed is to remove the \makeindex command from the top of the latex source. Any existing .ind file will still be input by \printindex but no indexing files will be written or deleted.
If you run TtH on a file that contains both a \makeindex command and a \printindex it will overwrite your file.ind. In the unusual situation where your index, file.ind, was created laboriously by hand and cannot be recreated, you should be very careful to remove the \makeindex command from the .tex file. For safety, of course, also save a copy of your file.ind somewhere else.
The \makeindex command, if present, will also cause TtH to add a linked entry called ``Index'' to the end of any table of contents. This entry is a highly desirable feature for an HTML file, but if there is no \printindex command at the end of the document, the index will not exist, so the reference will be non-existent.
On some operating systems with file name length restrictions, the makeindex program is called makeindx. Therefore a TtH switch is provided: -xcommandline, which substitutes commandline for the default call makeindex. Therefore, -xmakeindx will switch to the correct program name on one of these limited operating systems. This switch also allows additional parameters or switches to be passed to makeindex via e.g. -x"makeindex -s style.sty". If you don't have the makeindex program, you can't create indexes with TtH or LaTeX, except by hand.
All of the index file processing naturally requires that TtH have write permission for the directory in which the original latex file (specified by the -L switch) resides.
Optionally TtH can use more appropriate graphics format, possibly using a user-supplied (script or) program called ps2gif to convert the postscript file to a gif file, ``file.gif''. When the switch -e1 or -e2 is specified, if ``file.gif'' or ``file.jpg'' already exists in the same directory as implied by the reference to ``file.ps'' then no translation is done and the file found is used instead. That gif (or jpg) is then automatically either linked (-e1) or inlined (-e2) in the document. If no gif or jpg is found, ps2gif is called. A linux (un*x) ps2gif script using Ghostscript and the pbmplus utilities for this purpose is included with the distribution. A comparable batch program can be constructed to work under other operating systems or else the translation can be done by hand. Naturally you need these utility programs or their equivalent on your system to do the conversion. The calling command-line for whatever ps2gif is supplied must be of the form: ps2gif inputfile.ext outputfile.ext. The program must have permission to write the outputfile (file.gif) in the directory in which the file.ps resides.
The Latex command \includegraphics{...} does exactly the same thing. Its optional arguments are ignored. \[e]psfig{file=...} is also treated the same.
If the extension of the file initially specified is not .ps or .eps, no conversion is done but the file is referenced or in-lined as an image. In effect, then, TtH supports postscript, encapsulated postscript, gif, and jpeg, plus any future formats that become supported by common browsers. However, LaTeX does not support these other formats, so it will give an error message if it can't find a postscript file, unless you specify the bounding box, thus preventing LaTeX interrogating the file.
Some TeX capabilities are extremely difficult or impossible to translate into HTML, because of browser limitations, and are best avoided if possible. Arrays or matrices in in-line equations cannot be properly supported because tables cannot be placed in-line in HTML. TtH output will be strangely disjointed. Likewise built-up fractions, most over- and under-accents, and indeed anything that requires specific placement on the page other than simple subscript or superscript and underline, cannot be rendered in-line in HTML, although TtH will render them well in displaystyle. These latter constructs are nevertheless commonly used in in-line TeX. TtH adopts the default policy of indicating in an unambiguous and relatively intuitive way what construct is being used (as opposed to simply omitting it). For example $\hat{a}$ is rendered [^a]. The result is rarely elegant. Therefore in authoring TeX that is known to be destined for HTML translation, one should bear in mind these limitations, and use an appropriate style.
As an option, TtH provides switch -t to convert inline
equations that use built-up constructs into a sort of half display,
half in-line equation. Each time a new in-line equation is encountered
[$ ... $ or \( ... \)] that needs to be built up, an
HTML table that starts a new line is begun, and the text then flows on
afterwards. For example
| 1 2 + n |
Although TtH supports a remarkably complete subset of LATEX, it does not support all of the complicated primitive details of TEX, partly because that would be unnecessary. For example, practically any TEX that redefines character codes will break because TtH knows nothing about the concept of character codes. (If you don't know much either, about this unfortunate aspect of TEX, join the vast majority of TEX users!) A related example is that TtH expects only letters or @ in user-defined command names, not punctuation characters etc.
Delimited parameter definitions are supported but the matching of parameter templates is not 100% compatible with TeX in respect of compression of space around commands, which is particularly obscure in TeX. Generally, removal of redundant whitespace in the argument pattern (and in its usage, of course) will improve compatibility. The recognition of these definitions can be disabled using the -d switch, in which case the definitions are simply discarded.
Although global macro definitions are supported by TtH, if they
contain conditional or other unsupported constructs,
it is often better to leave the definitions in a
file on the texinputs path. The file will then not be found by TtH. That
provides a mechanism to include the definitions when ``TeX''ing the
file, but not when ``TtH''ing it. If the definition is required in
TtH, the full path should be specified relative to the directory from
which TtH is run, e.g.
\input /home/myhome/mytexdir/mymacro.tex.
Unrecognized or undefined commands of the form \dothis{one}{two}{three}, are treated by discarding all the following adjacent brace groups. A space between the close and open braces will terminate the discarded arguments and cause the following brace group(s) to be scanned as if just the text. This makes it possible to use formatting to make TeX code come out right in both TeX and HTML. For example if TtH encounters a command written ``\boxthis{width} {boxed material}'' which might be designed in TeX to provide a width to a defined command, written with a space after the first argument, it will ignore the width and scan the boxed material into the text.
In TtH (unlike TeX) most built-in commands can not normally be redefined; any redefinition will simply be ignored (except inside edef and a few other places). This prevents TtH from safely allowing use of major packages that redefine standard TeX commands. For example amsTeX redefines footnote to have just one argument, which will cause problems. This particular example is potentially a problem with LaTeX too, which also redefines footnote. TtH handles this by keeping track of whether the file is LaTeX or TeX; therefore you should not mix the two dialects in a single file even though there is no need to tell TtH explicitly which type the file is. (Besides, a mixed file will play havoc with TeX itself.)
Sometimes TEX files use special macro packages designed for a specific layout of journal or conference. If such a macro package in its original form uses conditionals or other unsupported constructs, it may be inadvisable to use it. (For example, amsppt.sty which is full of unsupported constructs will certainly cause errors with TtH.) A different, simpler, version of the macro package, designed with the capabilities of TtH in mind, may readily be substituted when using TtH for translation. One way to do this is to leave the original macro or style file on the texinputs path so it is not accessed by TtH, but to prefix the alternative package for TtH. This can be done without alteration of the original TEX files by using, for example, the following command line:
cat alternate.macros file.tex | tth >output.htmlAlternatively a line can be added to the top of the TeX file of the form
%%tth:\input /full/path/to/alternate.macros
which will be ignored by TeX.
Since it is impossible to anticipate all style file incompatibilities, it must be the responsibility of the user (or the journal) to decide how to translate the concepts implemented in the original complicated macro package into simpler, TtH-compatible, TEX macros.
In summary, you might want to tell people viewing your documents to set their browsers to View Encoding MacRoman, and Edit Preferences Fonts Use-document-fonts (NS 4.0).
Symbol fonts are not normally enabled for Netscape running under X, because of the way Netscape groups its fonts. A fix for this is to install some aliases in the fonts directories or else to add a line to your .Xdefaults file. See http://venus.pfc.mit.edu/tth/Xfonts.html. You might want to put these notes on your site for people viewing your documents.
In Netscape 3.0 under X, for example, the printing fonts are hard coded into the browser and the font-changing commands are ignored when printing. For that reason, visitors viewing TtH documents will often not be able to print readable versions of documents with lots of mathematics. This problem could, and should, be fixed in the browsers. However, if you want your readers to be able to print a high-quality paper copy of the file, then you probably want to make available to them either the TeX source or a common page-description format such as Postscript or PDF. Since HTML documents download and display so much faster and better than these other formats on the screen, TtH's translation provides the natural medium for people to browse, but not necessarily the best medium for paper production.
Under Wind*ws, both Netscape (3.0) and Internet Explorer (3.02) incorrectly size or space vertically the symbol glyphs so that small gaps appear between the parts of large symbols and delimiters. This occurs only at certain font sizes (different between the two browsers!) but causes a slightly annoying degradation of the appearance.
Both Netscape and IE fail (although somewhat differently) to carry font changing commands from cell to cell of HTML3.2 tables. In rendering equations (using tables) TtH circumvents this bug at the cost of significant extra effort and slightly verbose HTML. However, for tables generated by \halign or \begin{tabular} TtH takes no special steps to avoid this bug. Therefore you cannot, for example, increase the font size of an entire table by enclosing it in {\large ... } and indeed the table will revert to the default size even if it is inside a different sized section of text. Moreover, a change of font face in a cell, for example by \it will not carry over to the next cell. A document containing this problem will not pass some HTML validations. It is prevented if every cell of a TeX table is enclosed in braces and the required style applied separately to every cell - a serious annoyance.
IE can become confused about its vertical alignment in tables, with the result that symbols float above or below the horizontal line in built-up equations. This sometimes fixes itself if you simply refresh the page!
%%tth:\begin{html}<title>Put the title here</title>\end{html}
This line will be ignored by TeX.
Even if this practice is ignored, or some other TeX usage causes a violation of the formal standard, the browsers will render the output correctly if this manual is followed.
Known limitations are significant but mostly covered above. I would be interested to hear about bugs but only if reports are accompanied by the brief section of TeX code that causes the problem. Ungraceful failures to parse straightforward TeX code are of most interest. Aesthetic critiques (with TeX code) will be considered for future improvements. Failures on complicated macros are to be expected. It is now very difficult to crash TtH by exceeding array bounds. I would like to hear about it if you succeed, especially if the code gives no error with TeX. I would be glad to receive LaTeX2e files (emailed to hutch@pfc.mit.edu) that illustrate LaTeX bugs. But please don't send LaTeX2.09 files or files that do not conform to the latest (1994) LaTeX users' guide.
The code has been compiled and run on Linux 2.0, MSDOS, Open VMS and sundry other operating systems. See http://hutchinson.belmont.ma.us/tth/platform.html.
TtH is copyright © Ian Hutchinson, 1997-8 (hutch@pfc.mit.edu).
You may freely use this software for non-commercial purposes. It may not be used for commercial purposes without an additional license. If you distribute any copies, you must include this file and these conditions must apply to the recipient. No warranty of fitness for any purpose whatever is given, intended, or implied. You use this software entirely at your own risk. If you choose to use TtH, by your actions you acknowledge that any direct or consequential damage whatever is your responsibility, not mine.
Many thanks for useful discussions and input to Robert Curtis, Ken Yap, Paul Gomme, Bruce Lipschultz, Mike Fridberg, Michael Sanders, Michael Patra, Bryan Anderson, Wolfram Gloger, Ray Mines, John Murdie, David Johnson, Jonathan Barron, Michael Hirsch, Jon Nimmo, Alan Flavell, Ron Kumon, Magne Rudshaug.
The following macro definitions, although not needed for TtH, will enable a TeX file that uses the non-standard TtH commands to be correctly parsed by Plain TeX.
\def\title#1{\bgroup\leftskip 0 pt plus1fill \rightskip 0 pt plus1fill
\pretolerance=100000 \lefthyphenmin=20 \righthyphenmin=20
\noindent
#1
\par\egroup}% Centers a possibly multi-line title.
\let\author=\title % Actually smaller font than title in LaTeX.
\input epsf % PD package defines \epsfbox for figure inclusion
\def\href#1#2{\special{html:<a href="#1">}{#2}\special{html:</a>}}
% Macro for http reference inclusion, per hypertex.
\def\tthdump{} % Do nothing.
Why won't TtH run under DOS? Something about DPMI.
It will, but the distributed DOS executable needs DPMI memory
extension support to run. Plain old DOS doesn't have that unless you
specifically load it. All Wind*ws versions from 3.1 on support it at
the DOS prompt.
Why won't TtH run from Program Manager in Wind*ws?
You need a command line. Call up the DOS prompt.
TtH does not recognize tableofcontents, backward
references, listoffigures, ...
Yes it does, see section 4.2, and use the -L switch.
TtH does not insert my picture environments.
If picture environment pictures are to be included, conversion to a gif file
is needed. See 4.5.
TtH messes up my tabbing environment.
Tabbing is not currently supported. It is alien to the HTML document
mark-up approach.
How do I make TtH border my tabular table?
TtH looks in the format string argument of the begin{tabular}
environment and if it begins with a | (vertical bar) then the HTML
table is bordered.
TtH inserts the title and author even without the
maketitle command
True, TtH inserts them when you define them. This gives you a chance
to fine-tune the presentation if you wish.
There seems to be a bug in \dot
\hat \tilde \frac
\vec ...
Neither over and under accents nor built-up constructs such as
fractions can be rendered in-line (i.e. in a textstyle equation
produced by $ ... $) in HTML. Therefore, TtH outputs something that is
not elegant but reasonably indicates the original
intention. Additional brackets are inserted to ensure that fractions
are unambiguous. TtH will render all these built-up constructs
correctly in a display equation. See also 4.6 for an option.
Why does the large square root sign look so ugly?
There are some things that browser symbol fonts can't do well.
How do I insert code that is used only by TtH, not TeX?
Use %%tth: followed by the material you wish to pass to TtH.
TeX omits this as a comment.
How do I insert HTML tags into my file without TeX knowing?
Use %%tth: then on this line put
\begin{html} tags \end{html}. Do not try to continue this
html onto a second line with a second %%tth: before the
\end{HTML} because the html environment will output the
%%tth:, which it probably not what you want. Another way to
pass codes directly to the output is the \special{html: ... }
command. Do
not use \begin{verbatim} to pass HTML tags. It will
convert the greater than and less than signs to make them appear in
the display and not be interpreted as tags.
How do I insert code that is used only by TeX, not TtH?
Insert the definition \def\tthdump{} at the top of the file and
then use \tthdump{TeX material} to pass stuff only to TeX.
Thus, for example, the following will output alternate versions from
TeX and TtH.
\def\tthdump{}
%%tth:\begin{html}<H1>The HTML Header</H1>\end{html}
\tthdump{\beginsection{The TeX Header}\par}
How do I include the style file ...sty for the TeX paper I prepared for... journal?
If you are wise, you probably don't. TtH often can't handle
complicated journal formats for [La]TeX without modification, because
they frequently use conditionals, character code modification or
other unsupported constructs. Instead, look at your TeX file, or the
TtH messages telling you which commands are unknown. Decide
which of the journal's specific commands or environments you used or
need. Write a little style file that defines them to do something
simple and sensible, or translates them into standard LaTeX commands,
without conditionals. Or ask the journal to provide such a style
file! If you are a journal publisher, distribute your simplified
style file to your authors.
Why does TtH not recognize my ends of lines properly?
If you transfer a file from one operating system to another as a
binary file, the line-end codes are likely to be messed up. They use
different codes on Un*x, DOS, and Mac. Usually TeX is not bothered by
this. TtH is somewhat more sensitive. Use ASCII transfer.
TtH does not recognize evironment ... even though it
claims to.
Probably you left a spurious space, e.g. \begin {enumerate}
between the \begin and the following brace. TtH won't always
accept that, even though LaTeX does. It is bad style.
Why does not TtH recognize the longtable environment?
It is not part of the standard LaTeX2e.
The file I ``published'' using Netscape Composer looks
messed up when viewed on a Mac.
Don't use Composer on TtH documents. See section 6.2.
In bordered tables I want an empty cell to look
empty. How do I make TtH do that?
HTML tables by default ``fill in'' an empty cell, so that it gives the
visual impression of being absent. This is sometimes useful, so TtH
does not prevent it. If you want it to look like an empty cell, put a
non-break space in it by &~& in the TeX.
Why does TtH mess up my \fbox, minipage, etc?
The whole concept of a ``box'' is inappropriate for HTML. TtH tries to
take reasonable action on encountering one. But in some cases,
especially in equations, it can't cope.
Why does TtH complain about my skip, space, ... command?
Dimensions are inappropriate for HTML. TtH tries to remove all
dimension, space, and glue commands with the exception of bigskip,
medskip and smallskip.
How do I get caligraphic fonts, {\cal E}, AMS
fonts, etc?
You can't because browsers don't have access to them. TtH can only
support fonts that are available on the browsers that eventually visit
the page. By default TtH tells the browser to render caligraphic as
italic helvetica font.
Why does TtH turn double-quotes into an accent instead of quotes?
In basic TeX the double quotes character " is not defined, and hence may
do anything that the local installation feels like. Double quotes must
be inserted by using two quote '' or back-quote `` characters. In
German TeX implementations, the double-quotes character is used to
give the umlaut over accent. TtH supports this German use in
appropriate contexts. English speakers should adopt proper TeX quote
usage.
How do I include into a macro I am defining a # sign
for an HTML reference?
When you do \special{html:<a href="#reference">}
TtH just puts the html tag in the output verbatim. TeX does essentially the
same for its dvi file and the dvi processor later may or may not complain
about not understanding it; but generally it is ignored. However if you try
to define a macro like
\def\localhref{\special{html:<a href="#reference">}} then TeX
will complain as follows:
! Illegal parameter number in definition of \localref.
<to be read again>
r
l.3 \def\localref{\special{html:<a href="#r
eference">}}
? This problem is caused by TeX's syntax analysis of
the contents of the definition. One solution is to hide the
definition from TeX using %%tth:. An alternative definition
that avoids this problem must also be included for TeX's benefit, for
example thus:
\def\tthdump{}
\tthdump{\edef\localref{[a hyperreference]}}
%%tth:\def\localhref{\special{html:<a href="#reference">}}
Alternatively, use \# in place of # in the hypertex
reference. TtH specifically recognizes this as a literal and does
appropriate translation. For example
\def\localhref#1#2{\special{html:<a href="\##1">}#2\special{html:</a>}}
will use its first parameter as a local anchor reference, preceded by #, and its second as the text of the anchor.
1 Delimited definitions are not 100% TeX compatible
2 See appendix for TeX macros supporting these commands