s --> np, vp.

np --> pn.

np --> pro.

np --> det, n.

vp --> iv.

vp --> tv, np.

pn --> [fido].

n --> [dog];[bone].

pro --> [he];[it].

det --> [a].

iv --> [slept].

tv --> [is];[ate].


test :-
	findall(Sent,s(Sent,[]),Sents),
	count_sents(1,Sents).


count_sents(_,[]):-!.
count_sents(N,[A|Rest]):-
	write(N),tab(1),writeln(A),
	N1 is N +1,
	count_sents(N1,Rest).