the := word &
[ ORTH "the",
  HEAD det,
  SPR < >,
  COMPS < > ].

that := word &
[ ORTH "that",
  HEAD det & [ AGR [ NUM sing ] ],
  SPR < >,
  COMPS < > ].

those := word &
[ ORTH "those",
  HEAD det & [ AGR [ NUM plur ] ],
  SPR < >,
  COMPS < > ].

dog := word &
[ ORTH "dog",
  HEAD noun & [ AGR #1 & [ NUM sing,
                           PER 3rd ] ],
  SPR < [HEAD det & [ AGR #1 ] ] >,
  COMPS < > ].

dogs := word &
[ ORTH "dogs",
  HEAD noun & [ AGR #1 & [ NUM plur,
                           PER 3rd ] ],
  SPR < [HEAD det & [ AGR #1 ] ] >,
  COMPS < >  ].

cat := word &
[ ORTH "cat",
  HEAD noun & [ AGR #1 & [ NUM sing,
                           PER 3rd ] ],
  SPR < [HEAD det & [ AGR #1 ] ] >,
  COMPS < > ].


barks := word &
[ ORTH "barks",
  HEAD verb,
  SPR < [HEAD noun & [ AGR [ NUM sing,
                             PER 3rd ] ] ] >,
  COMPS < > ].

;;; Notice that the agreement information on the SPR of "bark" is incorrect.  What would happen if we put "I" in the lexicon?  As an exercise try to implement the 3sing / non-3sing type distinction described in the Sag & Wasow textbook.  The tricky thing with the definition described in the book is that nothing stops non-3sing from unifying with [ PER 3, NUM sing ]. 

bark := word &
[ ORTH "bark",
  HEAD verb,
  SPR < [HEAD noun & [ AGR [ NUM plur ] ] ] >,
  COMPS < > ].

chased := word &
[ ORTH "chased",
  HEAD verb,
  SPR < [HEAD noun] >,
  COMPS < phrase & [HEAD noun] > ].