How to modify a math-mode column type to use teletype letters by default?

Question

With normal text, I have the choice between \texttt{…}, which applies the font change to an argument, and \ttfamily, which applies it to the rest of the group.

In math mode, I have the former, with \mathtt{…}. What is the equivalent of \ttfamily in math mode?

(Why can’t I use \mathtt? Because I want to apply the change in a >{…} column spec, together with lhs2Tex.)

Are you using one of the "standard" LaTeX document classes (article, report, book) or a document class that's based on one of these classes? If so, >{\tt} works just fine in math mode. — Mico, Feb 25 '18 at 19:47
@Mico actually that or in general \DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt} is perhaps a cleaner answer than mine (although it's the same thing really) you should probably post as answer. — David Carlisle, Feb 25 '18 at 20:08
@Mico voted! (somehow I hadn't seen your comment, although the site says it was posted 20min before my answer:-) — David Carlisle, Feb 25 '18 at 20:24

score 4 · Accepted Answer · answered Feb 25 '18 at 20:06

4

Probably an abuse of syntax but anyway you can use

\documentclass{article}

\begin{document}


$\mathtt{\global\count1\fam}\fam\count1 abc=xyz$

\end{document}

answered Feb 25 '18 at 20:06

David Carlisle

757,742

Mico · Answer 2 · 2018-03-01T11:48:53.453

1

If you use one of the "standard" LaTeX document classes (article, report, book) or a document class that's built on one of these classes, you could use >{\tt} as the "prefix" to the relevant column type. A full MWE (minimum working example):

\documentclass{article}
\usepackage{array}
\begin{document}
$\begin{array}{>{\tt}c}
   aaaa
\end{array}$
\end{document}

The KOMA-Script document classes (e.g., scrartcl, scrreport, scrbook) and the memoir class no longer define \tt. If you use one of these classes, you will also need to provide the following directive in the preamble:

\DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt}

as well as \usepackage{array}. A suitably modified MWE:

\documentclass{scrreprt} % or: \documentclass{memoir}
\DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt}
\usepackage{array}
\begin{document}
$\begin{array}{>{\tt}c}
   aaaa
\end{array}$
\end{document}

edited Mar 01 '18 at 11:48

answered Feb 25 '18 at 20:19

Mico

506,678

Interesting – how does \DeclareOldFontCommand turn a argument-expecting function \mathtt into one that extends to the end? – Joachim Breitner Feb 25 '18 at 21:00
For more on \DeclareOldFontCommand, see also this answer to the query Is there any reason not to use \let to redefine a deprecated control sequence to the currently recommended one? (Shameless self-citation alert!) See, in particular, the discussion, toward the end, of what \@fontswitch does. Basically, in a math context, \@fontswitch changes \mathtt from behaving like taking an argument to behaving like a switch, i.e., not taking an argument. – Mico Feb 25 '18 at 21:13

How to modify a math-mode column type to use teletype letters by default?

2 Answers2