Should \mathrm work in \gather* environment?

Question

I am trying to use \mathrm in gather* environment, but the result is text without any spaces. How can I correct that, please?

\documentclass{article} 
\usepackage{amsmath} 

\begin{document} 
\begin{gather*}
  P(A) = P(B) + P(C) \qquad \mathrm{4-momentum conservation}\\
  P(A) = \left( m_{A}, \vec{0} \right) \qquad \mathrm{in the rest frame of A}\\
  \Downarrow\\
\end{gather*}

\end{document}

\mathrm still sets content in math. You're looking for \text or perhaps \textrm or \mbox. — Werner, Mar 09 '15 at 19:21
Not only do you get no space - is set as a minus sign, not as a hyphen. — David Carlisle, Mar 09 '15 at 19:22
note this is unrelated to gather, you see the same in $\mathrm{a b c}$ — David Carlisle, Mar 09 '15 at 19:26

score 3 · Accepted Answer · edited Apr 13 '17 at 12:34

\mathrm does work in gather* and the output is as expected: it provides a math related roman (upright) font:

enter image description here

\documentclass{article} 
\usepackage{amsmath} 

\begin{document}

\begin{gather*}
  P(A) = P(B) + P(C) \qquad \mathrm{4-momentum conservation} \\
  P(A) = P(B) + P(C) \qquad \textrm{4-momentum conservation} \\
  P(A) = \bigl( m_{A}, \vec{0}\, \bigr) \qquad \text{in the rest frame of $A$} \\
  P(A) = \bigl( m_{A}, \vec{0}\, \bigr) \qquad \mbox{in the rest frame of $A$}
\end{gather*}

\end{document}

In fact, this output is completely unrelated to gather (and friends).

For alternatives to printing textual content in math mode, see Difference between various methods for producing text in math mode.

Should \mathrm work in \gather* environment?

1 Answers1