sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),[over,over],
{VP=verb_phrase(verb(N)),number(N)}.

noun_phrase(noun_phrase(D,N))-->determiner(D),noun(N).

verb_phrase(verb_phrase(V,NP))-->verb(V),noun_phrase(NP).
verb_phrase(verb_phrase(V))-->verb(V).

determiner(determiner(the))-->[the].
determiner(determiner(an))-->[an].
determiner(determiner(a))-->[a].

noun(noun(apple))-->[apple].
noun(noun(pear))-->[pear].
noun(noun(man))-->[man].

verb(verb(eats))-->[eats].
verb(verb(8))-->[8].
verb(verb(ate))-->[ate].
verb(verb(likes))-->[likes].

/*
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP).
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),['[',done,']'].
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),['.'].
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),['.'].
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),{VP=verb_phrase(verb(N)),number(N)},['.'].
sentence(sentence(NP,VP))-->noun_phrase(NP),verb_phrase(VP),{VP=verb_phrase(verb(N)),number(N)},['.'].

*/