/** Number

?- question([how,many,marbles,did,john,throw],[[john,threw,2,marbles],[john,threw,3,marbles]],Number).

C = 5 ;

I threw 2 marbles
I threw 3 marbles

[       
        [i,need,me],
        [       
                [i,need,2,marbles],[the,A,marbles,were,thrown,by,me]
        ]
]

**/

sentence_to_ontologies(Sentence,Ontologies) :-
	phrase(sentence(Ontologies),Sentence).

sentence(Ontologies) --> noun_phrase(Subject), verb_phrase(Verb1,Object),
	{subject_to_object(Subject,Object2),append(Verb1,[by,Object2],Verb),
	append_list([Subject,need,Object],Copremise1),
	append_list([the,Object,Verb],Copremise2), Ontologies=
	[       
        	[Subject,need,Object2],
        	[       
                	Copremise1,Copremise2
        	]
	]}.
subject_to_object(i,me).
noun_phrase(Noun) --> [Noun], {Noun=i}.
verb_phrase(Verb2,Object2) --> [Verb1], [A], [Object],
	{Verb1=threw, Object=marbles, verb_transform(Verb1,A,Verb2),
	append([A],[Object],Object2)}.

verb_transform(threw,A,[were,thrown]) :-
	number(A,plural).
number(1,singular).
number(2,plural).
number(3,plural).
value(
[
	[i,need,me],
       	[
          	[i,need,A,marbles],[the,A,marbles,were,thrown,by,me]
       	]
]
,A).

sum([Sentence1,Sentence2],C) :-
	sentence_to_ontologies(Sentence1,Ontologies1),value(Ontologies1,A),
	sentence_to_ontologies(Sentence2,Ontologies2),value(Ontologies2,B),
        
        C is A+B.

append_list([A|B],C) :-
        append_list([],[A,B],C).
append_list(A,[],A).
append_list(A,[[B1|B1s]|Bs],C) :-
        append_list(A,[B1|B1s],C1), append_list(C1,Bs,C), !.
append_list(A,[B|Bs],C) :-
        append(A,[B],C1), append_list(C1,Bs,C).