From: Mark Wooding Date: Tue, 20 Aug 2019 11:23:17 +0000 (+0100) Subject: doc/refintro.tex: Hoist $\epsilon$ to the top of the metasyntax section. X-Git-Url: https://git.distorted.org.uk/~mdw/sod/commitdiff_plain/f736d657b15a29500c61c28644de6b558c08d912 doc/refintro.tex: Hoist $\epsilon$ to the top of the metasyntax section. It's important, and liable to be lost otherwise. --- diff --git a/doc/refintro.tex b/doc/refintro.tex index 6b162bd..6d93b65 100644 --- a/doc/refintro.tex +++ b/doc/refintro.tex @@ -90,6 +90,11 @@ manual describes the base system as provided in the distribution. Fortunately, Sod is syntactically quite simple. The notation is slightly unusual in order to make the presentation shorter and easier to read. +The letter $\epsilon$ denotes the empty nonterminal +\begin{quote} + \syntax{$\epsilon$ ::=} +\end{quote} + Anywhere a simple nonterminal name $x$ may appear in the grammar, an \emph{indexed} nonterminal $x[a_1, \ldots, a_n]$ may also appear. On the left-hand side of a production rule, the indices $a_1$, \ldots, $a_n$ are @@ -111,11 +116,6 @@ exactly the same as $x[a_1, \ldots, a_n]$ with the additional rules \end{quote} where $a_1$, \ldots, $a_n$ are new nonterminal symbols. -The letter $\epsilon$ denotes the empty nonterminal -\begin{quote} - \syntax{$\epsilon$ ::=} -\end{quote} - The following indexed productions are used throughout the grammar, some often enough that they deserve special notation. \begin{itemize}