anchor.diff:    ;
   
   arg_list :  
  -     (arg) (t_FILLER? t_COMMA t_FILLER? arg)*
  -  ;
  -  
  -arg :
  -     expr
  -  |  t_COLON
  +     expr (t_FILLER? t_COMMA t_FILLER? expr)*
     ;
   
   literal :
  
positive.code: expr :
       short_or_expr
    |  t_AT t_FILLER? input_params t_FILLER? expr
    ;
  
  short_or_expr :
  
negative.code:   |  cell_array
    |  access
    |  t_AT t_FILLER? name
    |  t_END //really only applies in args, but let Natlab handle that
    ;
  
  access :
  