s := phrase & [ HEAD verb, SPR <>, COMPS <>, GAP <! !> ].

s-np := phrase & [ HEAD verb, SPR <>, COMPS <>, 
          GAP <! [ HEAD noun, SPR <>, COMPS <> ] !> ].

s-pp := phrase & [ HEAD verb, SPR <>, COMPS <>, 
          GAP <! [ HEAD prep, SPR <>, COMPS <> ] !> ].

vp := phrase & [ HEAD verb, SPR < [] >, COMPS <>, GAP <! !> ].

vp-np := phrase & [ HEAD verb, SPR < [] >, COMPS <>, 
          GAP <! [ HEAD noun, SPR <>, COMPS <> ] !> ].

vp-pp := phrase & [ HEAD verb, SPR < [] >, COMPS <>,
          GAP <! [ HEAD prep, SPR <>, COMPS <> ] !> ].

v := [ HEAD verb ].

np := phrase & [ HEAD noun, SPR <>, COMPS <>, GAP <! !> ].

np-np := phrase & [ HEAD noun, SPR <>, COMPS <>, 
           GAP <! [ HEAD noun, SPR <>, COMPS <> ] !> ].

np-pp := phrase & [ HEAD noun, SPR <>, COMPS <>, 
           GAP <! [ HEAD prep, SPR <>, COMPS <> ] !> ].

n := [ HEAD noun, SPR < [] >, GAP <! !> ].

n-np := [ HEAD noun, SPR < [] >,
          GAP <! [ HEAD noun, SPR <>, COMPS <> ] !> ].

n-pp := [ HEAD noun, SPR < [] >,
          GAP <! [ HEAD prep, SPR <>, COMPS <> ] !> ].

det := [ HEAD det ].

pp := phrase & [ HEAD prep, SPR <>, COMPS <>, GAP <! !> ].

pp-np := phrase & [ HEAD prep, SPR <>, COMPS <>, 
           GAP <! [ HEAD noun, SPR <>, COMPS <> ] !> ].

pp-pp := phrase & [ HEAD prep, SPR <>, COMPS <>, 
           GAP <! [ HEAD prep, SPR <>, COMPS <> ] !> ].

p := [ HEAD prep ].