% -*-Prolog-*- :- dynamic ('-->>')/2. :- dynamic ('--*>>')/2. % a simple pfc dcg grammar. requires dcg_pfc.pl % backward grammar rules. s(s(Np,Vp)) -->> np(Np), vp(Vp). vp(vp(V,Np)) -->> verb(V), np(Np). vp(vp(V)) -->> verb(V). vp(vp(VP,X)) -->> vp(VP), pp(X). np(np(N,D)) -->> det(D), noun(N). np(np(N)) -->> noun(N). np(np(Np,pp(Pp))) -->> np(Np), pp(Pp). pp(pp(P,Np)) -->> prep(P), np(Np). % forward grammar rules. P --*>> [W],{cat(W,Cat),P =.. [Cat,W]}. % simple facts. cat(the,det). cat(a,det). cat(man,noun). cat(fish,noun). cat(eats,verb). cat(catches,verb). cat(in,prep). cat(on,prep). cat(house,noun). cat(table,noun).