paralist

gistfile1.tex

\documentclass{article}

\usepackage{nth}
\usepackage{paralist}

% Use \parenpointedenum *before* the \begin{inparaenum} environment
% to make the labels (X.Y.Z).
\makeatletter
\def\parenpointedenum{%
  \pl@pointxxxenum
  \def\labelenumi{(\theenumi)}%
  \def\labelenumii{(\theenumii)}%
  \def\labelenumiii{(\theenumiii)}%
  \def\labelenumiv{(\theenumiv)}%
}
\makeatother


\begin{document}

\parenpointedenum\begin{inparaenum}
\item Start at nonterminal $Expression$
\item Select the $\nth{3}$ alternative
\item Output terminal \textbf{``(''}
\item Call the left-hand $Expression$ recursively
 \begin{inparaenum}
 \item Select the $\nth{2}$ alternative
 \item Output terminal \textbf{``(''}
 \item haha
 \end{inparaenum}
\item huhu back to 5!
\end{inparaenum}

Goal:

(1) Start at nonterminal Expression
(2) Select the 3nd alternative
(3) Output terminal ``(''
(4) Call the left-hand Expression recursively
(4.1) Select the 2nd alternative
(4.2) Output terminal ``(''
(4.3) haha
(5) huhu back to 5!
\end{document}