# How to un-italicise Bulletpoints

\begin{proposition}

An elliptic curve given by a Weierstrass equation

\begin{itemize}
\item[(a)]{is nonsingular iff $\Delta_E\neq0$.}
\item[(b)]{has a node iff $\Delta_E=0$ and $c_4\neq0$.
\item[(c)]{has a cusp iff $\Delta_E=c_4=0$.}
\end{itemize}
\end{proposition}

Because this is written as a proposition, all the text is italicised. At the same time, so are the bullet points (a),(b),(c). What do I do to remove the italics on the bullet points but still keep the text italicised as per normal.

When it is written as a definition, there isn't a problem as the original text in the definition is not italicised.

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You could use the enumitem package, an enumerate environment with label=\normalfont(\alph*) passed in the optional argument. –  A.Ellett Jul 31 '14 at 20:01
Where do people get the idea that they should use \item[(a) ]. I've seen several use this lately so I'd like to know where the idea comes from so we can get that idea fixed –  daleif Jul 31 '14 at 20:26

\documentclass{article}
\usepackage{amsthm}
\newtheorem{proposition}{Proposition}
\begin{document}
\begin{proposition}
An elliptic curve given by a Weierstrass equation
\begin{enumerate}
\renewcommand\labelenumi{\normalfont(\alph{enumi})}
\item is nonsingular iff $\Delta_E\neq0$.
\item has a node iff $\Delta_E=0$ and $c_4\neq0$.
\item  has a cusp iff $\Delta_E=c_4=0$.
\end{enumerate}
\end{proposition}
\end{document}

Now the labeling is automatic. If you move the redefinition of \labelenumi to the preamble it will affect all first level (i.e. not nested) enumerate environments.

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What would I put if I want the numbering to be in numerals instead? :) –  Haikal Yeo Jul 31 '14 at 20:09
For Roman numerals, change \alph to \roman or \Roman. For arabic numerals (1,2,...) use \arabic. –  Ian Thompson Jul 31 '14 at 20:10

You should use enumitem:

\documentclass{article}
\usepackage{amsthm}
\usepackage{enumitem}

\newtheorem{proposition}{Proposition}
\newenvironment{conditions}[1][\alph]
{\begin{enumerate}[label=\upshape(#1*)]}
{\end{enumerate}}

\begin{document}

\begin{proposition}
An elliptic curve given by a Weierstrass equation
\begin{conditions}
\item is nonsingular iff $\Delta_E\neq0$.
\item has a node iff $\Delta_E=0$ and $c_4\neq0$.
\item  has a cusp iff $\Delta_E=c_4=0$.
\end{conditions}
\end{proposition}

\begin{proposition}
The following conditions are equivalent:
\begin{conditions}[\arabic]
\item pigs can fly,
\item donkeys have short ears,
\item the moon is made of Swiss cheese.
\end{conditions}
\end{proposition}

\end{document}

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what does \upshape do? –  Haikal Yeo Jul 31 '14 at 20:35
@HaikalYeo It's the command for telling LaTeX to use the upright font. –  egreg Jul 31 '14 at 20:56

What about changing the itemize environment for a enumerate one. Then we personalize this particular environment just to not interfere with other enumerate environtments. Just like this:

\documentclass{article}
\usepackage{amsthm}
\usepackage{enumitem}

\newtheorem{proposition}{Proposition}

\begin{document}

\begin{proposition}

An elliptic curve given by a Weierstrass equation

\begin{enumerate} [label=\rmfamily\emph{(\alph*)}]
\item   {is nonsingular iff $\Delta_E\neq0$.}
\item   {has a node iff $\Delta_E=0$ and $c_4\neq0$}.
\item   {has a cusp iff $\Delta_E=c_4=0$.}
\end{enumerate}
\end{proposition}

\end{document}

The label part do the work, leaving the changes just for this environment. The result is this:

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