;;; Rules
s_rule := phrase &
[ CATEG s,
  ARGS [ FIRST [ CATEG np ],
         REST [ FIRST [ CATEG vp ],
                REST *null* ]]] .

np_rule := phrase &
[ CATEG np,
  ARGS [ FIRST [ CATEG det ],
         REST [ FIRST [ CATEG n ],
                REST *null* ]]] .