;;; Lexicon
this := word &
[ ORTH "this",
  CATEG det ].

these := word &
[ ORTH "these",
  CATEG det ].

sleep := word &
[ ORTH "sleep",
  CATEG vp ].

sleeps := word &
[ ORTH "sleeps",
  CATEG vp ].

dog := word &
[ ORTH "dog",
  CATEG n ].

dogs := word &
[ ORTH "dogs",
  CATEG n ].