grammar 
terminals :: '' ::=
  | <                                   :: :: lt
    {{ tex \ensuremath{\langle} }}
%    {{ tex \ottsym{<} }}
  | >                                   :: :: gt
    {{ tex \ensuremath{\rangle} }}
%    {{ tex \ottsym{>} }}

%   | [| :: :: range_start
%     {{ tex \mbox{$\ottsym{[\textbar}$} }}       
%   | |] :: :: range_end       
%     {{ tex \mbox{$\ottsym{\textbar]}$} }}       
%   | [|| :: :: list_start
%     {{ tex \mbox{$\ottsym{[\textbar\textbar}$} }}       
%   | ||] :: :: list_end       
%     {{ tex \mbox{$\ottsym{\textbar\textbar]}$} }}       

  | ->                                  :: :: arrow
    {{ tex \ensuremath{\rightarrow} }}
%    {{ tex \ottsym{-\textgreater} }}
    {{ com \texttt{->} }}

  | >=                                  :: :: geq
    {{ tex \ensuremath{\geq} }}
%    {{ tex \ottsym{\textgreater=} }}
    {{ com \texttt{>=} }}
  | '<='                                        :: :: leq
    {{ tex \ensuremath{\leq} }}
%    {{ tex \ottsym{\textless=} }}
    {{ com \texttt{<=} }}