\
mbox
or \
textrm
:
$e = mc^2 \mbox{here we go again}$
The problem is that, with either, the size of the text remains firmly at the surrounding text size, so that
$z = a_{\mbox{other end}}$
can look quite painfully wrong.
The other simple technique,\
textrm
, is no more promising:
$z = a_{\textrm{other end}}$
does the same as \
mbox
, by default.
\
mathrm
) gets the
size right, but since it’s intended for use in maths, its spaces get
ignored — use \
mathrm
for upright roman alphabetic variable
names, but not otherwise.)
You can correct these problems with size selectors in the text, as:
$z = a_{\mbox{\scriptsize other end}}$
which works if your surrounding text is at default document size, but gives you the wrong size otherwise.
The\
mbox
short cut is (just about) OK for “occasional”
use, but serious mathematics calls for a technique that
relieves the typist of the sort of thought required. As usual, the
AMSLaTeX system provides what’s necessary — the \
text
command. (The command is actually provided by the amstext
package, but the “global” amsmath package loads it.) Thus
anyone using AMSLaTeX proper has the command available, so even
this author can write:
\usepackage{amsmath} ... $z = a_{\text{other end}}$
and the text will be at the right size, and in the same font as
surrounding text. (The amstext package also puts
\
textrm
to rights — but \
text
is easier to type than
\
textrm
!)
\
intertext
command. For example:
\begin{align} A_1&=N_0(\lambda;\Omega')-\phi(\lambda;\Omega'),\\ A_2&=\phi(\lambda;\Omega')-\phi(\lambda;\Omega),\\ \intertext{and} A_3&=\mathcal{N}(\lambda;\omega). \end{align}
places the text “and” on a separate line before the last line of the
display. If the interjected text is short, or the equations
themselves are light-weight, you may find that \
intertext
leaves
too much space. Slightly more modest is the \
shortintertext
command from the mathtools package:
\begin{align} a =& b \shortintertext{or} c =& b \end{align}
To have the text on the same line as the second equation, one can use
the flalign
environment (from amsmath)
with lots of dummy equations (represented by the double &
signs):
\begin{flalign} && a =& b && \\ \text{or} && c =& b && \end{flalign}
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=mathstext