How to make this prolog program right

Hello, here is what I have done, basically, when I query

valueEach([],_,[]).
valueEach([H|T], Slot, [R|Rest]) :-
value(H,Slot, V),
!, % to skip execution of the next valueEach predicate, but the
problem is it does not look for the alternative of value(indonesia,
has_city, denpasar) in this query.
R = [H,Slot,V],
valueEach(T, Slot, Rest)

You have to collect all value/3 for same first argument.

valueEach([],_,[]).
valueEach([H|T], Slot, Result) :-
collectEach(H,Slot,[],L),
valueEach(T, Slot, Rest),
append(L,Rest,Result).

collectEach(H,Slot,PartialL,L):-
value(H,Slot,V),
\+(member([H,Slot,V],PartialL) ),
collectEach(H,Slot,[[H,Slot,V]|PartialL],L),
!.
collectEach(_H,_Slot,L,L).

value(indonesia,has_city,jakarta).
value(indonesia,has_city,denpasar).
value(usa,has_city,new_york).

?- valueEach([indonesia,usa,india],has_city,L).

Regards,
Paul.

On Jun 29, 10:31*pm, "fodor.p...@gmail.com" <fodor.p...@gmail.com>
wrote:
> You have to collect all value/3 for same first argument.
>
> valueEach([],_,[]).
> valueEach([H|T], Slot, Result) :-
> * collectEach(H,Slot,[],L),
> * valueEach(T, Slot, Rest),
> * append(L,Rest,Result).
>
> collectEach(H,Slot,PartialL,L):-
> * value(H,Slot,V),
> * \+(member([H,Slot,V],PartialL) ),
> * collectEach(H,Slot,[[H,Slot,V]|PartialL],L),
> * !.
> collectEach(_H,_Slot,L,L).
>
> value(indonesia,has_city,jakarta).
> value(indonesia,has_city,denpasar).
> value(usa,has_city,new_york).
>
> ?- valueEach([indonesia,usa,india],has_city,L).
>
> Regards,
> Paul.

Thanks paul, I think that has solved my problem.