%% find_object(Descriptions,Area,Identity)
%% Finds an object's number for an object with a certain Area from Descriptions, which is a list of object number, bottom-left corner and top-right corner

%% find_object([[0,[0,0],[1,1]],[1,[0,2],[1,4]]],1,Identity).
%% Identity = 0;

find_object(Descriptions,Area,Identity) :-
	find_areas(Descriptions,[],Areas),
	member([Identity,Area],Areas).

%% find_areas(Descriptions,Areas1,Areas2)
%% Calculates the areas of object described in Descriptions, adds them to Areas1 and 
%% returns Areas2

find_areas([],Areas,Areas).
find_areas([[Identity,[X1,Y1],[X2,Y2]]|Descriptions],Areas1,Areas2) :-
	Area is (X2-X1)*(Y2-Y1), append(Areas1,[[Identity,Area]],Areas3),
	find_areas(Descriptions,Areas3,Areas2).