\newif\ifspace
\def\addspace{\ifspace \; \spacefalse \fi}
\def\token#1{\addspace\hbox{\tt #1} \spacetrue}
\def\nonterm#1{\addspace\nt{#1} \spacetrue}
\def\nt#1{\hbox{\sl #1\/}}
\def\brepet{\addspace\{}
\def\erepet{\}}
\def\boption{\addspace[}
\def\eoption{]}
\def\brepets{\addspace\{}
\def\erepets{\}^+}
\def\bparen{\addspace(}
\def\eparen{)}
\def\orelse{\mid \spacefalse}
\def\is{ & ::= & \spacefalse }
\def\alt{ \\ & \mid & \spacefalse }
\def\cutline{ \\ & & \spacefalse }
\def\sep{ \\[2mm] \spacefalse }
\def\emptystring{\epsilon}
\def\syntax{$$\begin{array}{rrl}\spacefalse}
\def\endsyntax{\end{array}$$}
\def\syntaxleft{$\begin{array}{rrl}\spacefalse}
\def\endsyntaxleft{\end{array}$}
\let\oldldots=\ldots
\def\ldots{\spacefalse\oldldots}
\def\synt#1{$\spacefalse#1$}