anchor.diff:    |  cell_array
     |  access
     |  t_AT t_FILLER? name
  -  //|  t_END //really only applies in args, but let Natlab handle that
  +  //|  {$expr_or_arg::isArg}? t_END
     ;
   
   access :
  
positive.code:   |  function
    ;
  
  //precedence from: http://www.mathworks.com/access/helpdesk/help/techdoc/matlab_prog/f0-40063.html
  //all binary operators are left associative so no special handling is required
  expr :
       short_or_expr
    |  t_AT t_FILLER? input_params t_FILLER? expr
    //|  t_COLON //really only applies in args, but let Natlab handle that
    ;
  
  short_or_expr :
  
negative.code:   ;
  
  arg_list :  
       arg (t_FILLER? t_COMMA t_FILLER? arg)*
    ;
  
  literal :
  