Subversion Repositories programming

/* A simple grammar for English sentences */

/* after Clocksin & Mellish, 4th edition, pages 204ff */

sentence(X) :- np(Y), vp(Z), append(Y,Z,X).

np(X) :- determiner(Y), noun(Z), append(Y,Z,X). 

vp(X) :- verb(Y), np(Z), append(Y,Z,X).

vp(X) :- verb(X).

determiner([the]).

noun([cat]).
noun([dog]).

verb([chases]).
verb([eats]).
verb([sings]).