Italic letters are too loose in math mode

Question

I want to type something like this page http://caml.inria.fr/pub/docs/manual-ocaml/expr.html. So I need to use \begin{align*} and \end{align*} which displays its contents math mode. Therefore italic font is needed. But when I type directly "value-path" for instance, its letters look very loose.

Does anyone know how to make its letters tighter?

Answer 1

An example using the syntax package:

\documentclass{article}
\usepackage{syntax}

\begin{document}
\begin{grammar}

<statement> ::= <ident> `=' <expr> 
\alt `for' <ident> `=' <expr> `to' <expr> `do' <statement> 
\alt `{' <stat-list> `}' 
\alt <empty> 
<stat-list> ::= <statement> `;' <stat-list> | <statement> 

\end{grammar} 
\end{document}

Answer 2

For "multiletter identifiers", use \mathit{expr}.

Answer 3

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{bera}
\usepackage{array}
\begin{document}
\begin{center}
\tabcolsep=1.4pt
\tabular[t]{@{} >{\itshape}l c >{\itshape}l @{}}
expr & ::= & value-path\\  
     &  |  & constant  \\
     &  |  & ( expr )  \\
\endtabular
\end{center}

\end{document}