# How to change text to normal font inside \itshape?

I have the following code:

\documentclass[11pt]{article}

\usepackage{enumerate}
\usepackage{amsmath}
\newenvironment{italic}{\begin{quote}\itshape}{\end{quote}}

\begin{document}

\begin{italic}
blablabla
\begin{displaymath}
\rad(R)=\{x\in R\mid x^n=0 \text{ where we consider } n\geq 1\}
\end{displaymath}
more blablabla

\begin{enumerate}
\item $x^n$ with $n=1$
\item $y^m$ with $m=2$
\end{enumerate}

\end{italic}

\end{document}


I'd like the blablabla to be italic, but the text in the mathematical environment (for example "where we consider" and "with") shouldn't be. In my document, I have quite a lot of these blablabla's between mathematical environments, so that's the reason why I use the self-defined italic environment: to save some time and don't have to use \textit or \itshape all the time.

How can I solve this? Is this a good approach?

Edit: I've updated my question and changed the title, because the code I gave in the beginning didn't really reflect my situation. My mistake... I've used the tip to declare rad as a mathematical operator.

• Isn't amsmath needed to use \text? – Ruben Nov 30 '13 at 23:53
• @Jeroen Are you trying to write the statement of a theorem? – egreg Dec 1 '13 at 0:23
• @egreg: Well, it's the formulation of an exercise, so it's not really a theorem. – Jeroen Dec 1 '13 at 0:25
• According to the standard typesetting rules, the words ”where we consider” should use the current font, italic in this case. Not “rad”, which is a math symbol and must be upright. – egreg Dec 1 '13 at 0:33
• @egreg: Really? That would solve my problem immediately! Where can I actually read these typesetting rules? Everyone talks about them, but I don't know where to find them... (sounds stupid) – Jeroen Dec 1 '13 at 0:42

The \textit macro does not generally control the appearance of the text in the math environment. That's done separately.

In math mode you can use

\mathrm{rad}


Or if this is to be the name of a function you can load the amsmath package in the preamble

\usepackage{amsmath}


and then in the body of the text call

\operatorname{rad}


If this is something you will want to call repeatedly you can define a command to accomplish this:

\usepackage{amsmath}


and then in the body of the document you can write

$\rad(R)=\{x\in R\mid x^n=0 \text{ with }n\geq 1\}$


If additionally you wish the with not to be set in italics, you can do something like

\text{\normalfont\ with }


or

\textnormal{ with }


You need to make this change within \text{...} because it inherits the style of the fonts outside of the math environment.

You should notice that \normalfont is a switch command like \bfseries which remains in effect until the end of the current group. As \textbf{...} corresponds to {\bfseries ....}, \textnormal{...} corresponds to {\normalfont ...}.

To answer your first question: It does not work because you are in math-mode. On the other hand, if you are not in math-mode, something like

\textit{Blablabla \normalfont{Normalfont Bla} More Bla}


won't work too because normalfont does not take an argument. Try this one to see the difference:

\documentclass{article}

\begin{document}
\textit{Blablabla {\normalfont Normalfont Bla} More Bla}
\end{document}


Moreover you don't need to use math in \textit:

\documentclass[11pt]{article}

\begin{document}
\textit{blablabla}
\begin{displaymath}
\mathrm{rad}(R)=\{x\in R\mid x^n=0 \text{ with } n\geq 1\}
\end{displaymath}
\end{document}


## Edit

\documentclass[11pt]{article}
\usepackage{amsmath}
\let\AMStext\text
\newenvironment{italic}
{\renewcommand{\text}[1]{\AMStext{\normalfont ##1}}
\begin{quote}\itshape}
{\end{quote}}

\begin{document}
\begin{italic}
blablabla
\begin{displaymath}
\rad(R)=\{x\in R\mid x^n=0 \text{ where we consider } n\geq 1\}
\end{displaymath}
more blablabla
\begin{enumerate}
\item $x^n \text{ with } n=1$
\item $y^m \text{ with } m=2$
\end{enumerate}
\end{italic}
\end{document}

• One can use \textnormal – egreg Nov 30 '13 at 23:43
• ... which takes one argument and would work in the way as \normalfont was used in the OP (just for completeness :-) – Ruben Nov 30 '13 at 23:51

What A. Ellet said can be simulated in a complete code snippet as follows. thm environment makes the enclosed text italic. As \text inherits the font from the outside environment, the text \text{ with } becomes italic as well. To change it back to normal font, use either \text{ \normalfont with } or \text{ \textnormal{with} }.

\documentclass[preview,border=12pt]{standalone}
\usepackage{amsmath,amssymb}

\newtheorem{thm}{Theorem}

\begin{document}
\begin{thm}[\textbackslash textnormal]
$\rad(R)=\{x\in \mathbb{R}\mid x^n=0 \text{ \textnormal{with} } n\geq 1\}$
\end{thm}
\begin{thm}[\textbackslash normalfont]
$\rad(R)=\{x\in \mathbb{R}\mid x^n=0 \text{ \normalfont with } n\geq 1\}$
\end{thm}
\end{document}


You can also change the symbol R by \mathbb{R} to make it clearer as a real number set. Does it seem to be more fancy?

Note: It is a community wiki answer, just to prevent me from getting reputation points whenever the readers vote it up.

• Actually, the R marks a ring, not the real number set. :) – Jeroen Dec 1 '13 at 0:29