{tex-core} is for questions that are independent of formats and macro packages. Such questions usually relate to low-level TeX programming or the behaviour of TeX at an underlying level. Note that even Plain TeX is a format in itself; for questions about it, use {plain-tex}.

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20
votes
1answer
479 views

How does a TeX engine read and render the input stream?

I am new to TeX programming and I have not finished reading the TeXBook yet. I need at a glance tutorial about how a TeX engine reads, processes, and produces its output. My mental model as a newbie ...
23
votes
1answer
341 views

The \lowercase trick

We have a number of questions or rather answers using (and explaining) the \lowercase “trick”. \begingroup \lccode`\~=`\. \lowercase{\endgroup\def~}#1{foo with #1} However, after reading on ...
4
votes
0answers
59 views

Namespace in luatex

Is it possible from luatex access registers where all names of command sequences are stored. Is it possible to pull out this list of names? I am looking for a way to trace how namespace changes during ...
3
votes
1answer
75 views

What can I do if I want to have a system for compilation to (AMS) LaTeX regarding restrictions to user-defined macros?

So I want to have a system where some user document is fully processed by TeX engine (full TeX engine!) and some data is collected to some helper file (saying "helper" just not make you think it's ...
76
votes
2answers
6k views

What's new in TeX, version 3.14159265?

The new Knuth TeX has been released in early this month, and its version number is 3.14159265 now. It can be downloaded here. What's new in this release? And a further-more question, where can one ...
7
votes
1answer
238 views

debug No room for a new \write problem

I have a template with an extensive documentation. (See TemplateDocumentation.pdf). It compiled several month ago. Now with updated packages it does not compile anymore because of the famous No room ...
8
votes
1answer
133 views

Cut last word from sentence one by one

I want to execute particular command for some space separated list as argument. And then execute the same command for the same list without last element and do it until list is empty. As extra point ...
6
votes
2answers
168 views

Counters and macros?

Not sure how I should post my question but here it is: I've seen that in plain TeX, \newcount is illegal inside a macro \definition. Is there a way to allocate a register inside a macro? Also, if I ...
3
votes
1answer
141 views

Can (La)TeX be a compelling technology for the humanities, journalism, and other non-technical disciplines? [closed]

All over the web, I see how LaTeX has been successful as a way of describing mathematical notation, which makes it pretty easy to argue that it is a compelling technology for science, technology, ...
6
votes
2answers
152 views

Allowing first undelimited argument to be empty

Consider the following macro definitions: \def\mymacro#1{\mymacroii#1\nil} \def\mymacroii#1#2\nil{% \ifx\\#1\\% empty% \else #1% \fi }% \mymacro{foo}% -> f \mymacro{} \bye This is ...
3
votes
1answer
57 views

Alignment problem or the height of one text line for \footnotesize text

I want to align the arrows so that it goes directly through the "x". How can I do this? It works if I use \normalsize font. The background is that I want to separate my Tikz document in text rows ...
8
votes
1answer
79 views

Hyphenation of the word “paraboloid”

It seems like my TeX does not hyphenate the word "paraboloid" on its own. After adding \hyphenation{para-boloid} (I hope that's the right hyphenation...) to the preamble everything is fine. My ...
23
votes
2answers
510 views

Backward definition of (La)TeX commands

Again and again I see, that TeXnicians define commands and do several things with them in the reverse order, I would do this as amateur. See this example: In his answer to scrpage2: Three ...
4
votes
6answers
395 views

A meta-language for LaTeX

Whenever I write TeX/LaTeX documents, I always find that annoying because I can't really focus on the content, It's not that I don't like TeX or what it does for me, it's just the fact that the ...
5
votes
1answer
220 views

Changing page margins in {pdf-,Xe-}TeX

In TeX, changing the \hsize and the \vsize changes the main text size and the page size of the dvi output. When I compile a document with pdftex or xetex, the page size remains at A4. How can I change ...
12
votes
2answers
370 views

All about \shipout

While reading about packages that allow to hook macros to certain events, I came across this command, \shipout. Searching on the internet didn't help a lot but if I'm not so wrong it's somehow related ...
6
votes
2answers
371 views

Can you do all what you want with TeX?

With LaTeX, I know you can put pictures in the documents, use different fonts, ... and practically do whatever you want (except the fact that your document must have a predefined style, imposed by the ...
6
votes
1answer
75 views

Getting the page breaks right for a \beginsection macro

I've found this code in the question No indent in the first paragraph in a section in Plain TeX \def\mysection#1{% \goodbreak \vskip2\baselineskip \noindent #1\par \nobreak ...
7
votes
3answers
184 views

How can I parse the first word in a token stream, token by token?

Some programming editors and IDEs highlight legal and illegal variable names in different ways. I wish listings easily allowed for such syntax checking and highlighting, but it doesn't, at least at ...
11
votes
1answer
142 views

XeTeXpicfile in vertical mode

Given a minimal like \line{% \vtop{\hsize=.6\hsize Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse tempor lectus sit amet laoreet convallis. Quisque at est lacinia, porttitor ...
0
votes
0answers
37 views

How can the following table be created in LaTeX [duplicate]

I have asked this question here, and asking it once again, as it was marked as duplicate, although it is different from the links that were pointed to be the same as the question. So, how can I ...
6
votes
3answers
135 views

Why cannot the word in the last column be centered

I have the following table: \begin{tabular}{|p{3cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}|} \hline \centerline {image} & \multicolumn{2}{c|}{ABC} & \multicolumn{2}{c|}{DEF} \\ \hline & ...
14
votes
2answers
188 views

What is the easiest way to modify catcodes in a string?

Assume that a token register contains a sequence of letter tokens, each having a catcode of 12. I want to store in a second token register the same sequence of letter token, altering some catcodes on ...
0
votes
0answers
29 views

Inserting a line break in a formula [duplicate]

I have the following formula in LaTeX: \begin{equation} =\sqrt[m]{\mid C_{new}\left(pi\right)-f\left(pi\right)\mid^{m}-\mid C_{k}\left(pi\right)-f\left(pi\right)\mid^{m} ...
5
votes
2answers
144 views

How to get character code defined with \let (! Improper alphabetic constant)

Here's a example with the "! Improper alphabetic constant" error: %% this is ok \newcount\mychar \mychar=\number`a\relax \showthe a % shows You can't use `the letter a' after \the ...
4
votes
2answers
118 views

How to define a command \exponent that transforms $\exponent^e$ to $a^eb^ec^e$?

I have tried to define a command $\exponent$ that would look for next exponent and would put a copy of this exponent after a, another after b and a last one after c. $\exponent^e$ would transform to ...
9
votes
3answers
317 views

How to force LaTeX only commands?

Recently, I learned that for a long time I have been doing all of my mathematics in LaTeX incorrectly! I was using the $ TeX commands instead of the \( and \) LaTeX commands! I immediately went back ...
3
votes
0answers
56 views

Tex document that displays its own source code [duplicate]

Just out of curiosity, I was wondering how it is possible to write a LaTeX document which, when compiled, generates a document that contains exactly its own source code (i. e. a quine). Since LaTeX ...
38
votes
2answers
495 views

How to implement (low-level) arrays in TeX

Update: I have revised my question based on the comment by Bruno Le Floch and some further research. As some may know, I'm implementing a huge TeX macro package which has to do a lot of internal ...
12
votes
1answer
265 views

What does \empty do? [duplicate]

What does it do and what are its applications? I am currently testing the subtitle of my beamer presentation for its string length to decide about line spacings. Could it be simpler using \empty? If ...
10
votes
1answer
107 views

TeX doesn't recognize built-in control sequences?

I'm trying to learn to build things from the ground-up with TeX (not LaTeX---I've used LaTeX before, so I know how easy a solution "\usepackage{amsthm}+\begin{theorem}" is) and I'm trying to build my ...
6
votes
0answers
78 views

Testing if inside \halign [closed]

I am trying to write a macro that has a different behavior when called from text mode, math mode, display math, and math tables. The first three are easy enough with \ifmmode and \mathchoice. But the ...
0
votes
0answers
173 views

Weird behaviour in Texmaker (Changing the papersize)

I'm trying to change the page size in a tex document (I want a letterpaper size). I'm using Texmaker and the sequence Latex -> Dvips -> ps2pdf and my code is \documentclass[letterpaper]{report} ...
9
votes
2answers
670 views

\llap (or \rlap) at the begining of an indented paragraph

If I use a \llap{text} command at the begining of an indented paragraph, the text is not indented and is put on the line above the paragraph. \documentclass{article} \begin{document} \parindent=2cm ...
1
vote
1answer
170 views

ConTeXt: How to display last page number (Page # of #) in header/footer?

In LaTeX, I could do something like: \fancyhead[R]{\HeaderFont{\thepage{}/\pageref{LastPage}}} and/or \fancyfoot[R]{\FooterFont{\thepage{}/\pageref{LastPage}}} How to achieve the same with ...
0
votes
1answer
137 views

ConTeXt: How to maximize width of column depending on fixed sizes of other columns?

In LaTex, I could do something like: \newcolumntype{C}[1] {>{\centering\let\newline\\\arraybackslash\hspace{0pt}}p{#1}} \newcolumntype{L}[1] ...
7
votes
1answer
778 views

\newcounter vs \newcount [duplicate]

What are the differences between \newcounter vs \newcount? So far as my knowledge goes \newcounter is from LaTeX and \newcount is from TeX. Also, I find that \newcounter has an optional automatic ...
11
votes
1answer
230 views

What is the function of \noalign?

The use of \noalign is quite common. For example here \noalign is used with \vskip{}to control the height of a table cell. How does \noalign work in general, and how does it work with \vskip? ...
5
votes
2answers
132 views

Obtaining “greedy” pattern-matching in macros

Consider the following input to TeX: This is TeX, Version 3.1415926 (TeX Live 2013) **\def\a#1\par{[#1]} *\def\b#1\par{(#1)} *\a\b five\par\par *\end Two definitions have the same delimiter, so ...
4
votes
1answer
79 views

Expanding a variable within a protected label

I have some trouble with expanding variables within a protected label. I need a automatisated caption with a label all inside a command. Within the caption I want to have a two digit number ...
9
votes
1answer
134 views

How can I create a better cryptogram environment?

I put together a macro that takes two arguments. The first argument is a string of letters which defines a cipher. The second argument is a message to be encrypted using this cipher. ...
10
votes
1answer
82 views

\toks register expansion issue - or is it?

I am trying to assemble a table that occurs multiple times throughout a document. It always consists of some fixed columns, followed by a set of columns that appear in one table but are not needed in ...
11
votes
2answers
193 views

Creating new primitives

Consider the following TeX: \tt ~~~[def]: \meaning\def \par ~~~[let]: \meaning\let \par [define]: \meaning\define \par ~[macro]: \meaning\macro \def\macro#1{some ...
4
votes
1answer
70 views

Can I expand a macro argument once without using a scratch register?

I'm still trying to get my head around how expansion works in TeX. One thing I can't figure out is how to expand a macro argument once without having to use a scratch register as an intermediate. As ...
5
votes
1answer
131 views

Using \show in nonstopmode causes TeXmaker to raise false alarms. Any fix?

I'm currently reading the TeXbook, and I use \show a lot to see how Knuth defined plain-TeX macros in terms of TeX primitives. For instance, to have access to the definition of \centerline, I would ...
8
votes
1answer
114 views

How do ligatures work?

The TeXbook doesn't explain ligatures more than presenting the existing ones, the same for TeX By Topic. So, how are they defined? Is there a third way besides active characters and control sequences ...
2
votes
0answers
146 views

Adding vedic accents in sanskrit in devanagari script in red color using Context - not working in all cases

Using the techniques described in Coloring combining characters without changing color of a base character I have been able to color red the vedic accents in sanskrit typesetting using ConTexT MIV. ...
12
votes
1answer
75 views

Tight connection of \vbox es

I don't understand why TeX put a thin whitespace between my two vertical boxes: \documentclass{article} \begin{document} \vbox to 1cm {\rule{1cm}{1cm}} \vbox to 1cm {\rule{1cm}{1cm}} ...
12
votes
2answers
229 views

Define a shortcut (-> to \rightarrow) in plain TeX

I'ld like to make -> a shortcut for \rightarrow. Is that possible with Plain TeX or has it to do with the loaded font?
12
votes
2answers
134 views

Document equivalence

What is the best way to determine, for two arbitrary input files, if they will result in the same compiled document (disregarding timestamp information and external files)? Context I'm attempting to ...