%% room1([sofa,television],[[living-room,[vase,sofa,television]],[kitchen,[sink,table,refrigerator]]],Room).
room1(Items1,RoomsItems1,Room) :-
        RoomsItems1 = [RoomItems|_RoomsItems2],
	RoomItems = [Room, Items2],
	room2(Items1,Items2).
room1(Items1,RoomsItems1,Room) :-
        RoomsItems1 = [RoomItems|RoomsItems2],
 	RoomItems = [_Room, RoomsItems2],
        not(room2(Items1,RoomsItems2)),
	room1(Items1,RoomsItems2,Room).
room2([],_Items2).
room2(Items1,Items2) :-
	Items1=[Item|Items3],
	member(Item,Items2),
	delete(Items2,Item,Items4),
	room2(Items3,Items4).