solution(Ylist):-sol(Ylist,
		[1,2,3,4,5,6,7,8],
		[1,2,3,4,5,6,7,8],
		[-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7],
		[2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]).
sol([ ],[ ],Dy,Du,Dv).
sol([Y|Ylist],[X|Dx1],Dy,Du,Dv):-del(Y,Dy,Dy1),
				U is X-Y,
				del(U,Du,Du1),
				V is X+Y,
				del(V,Dv,Dv1),
				sol(Ylist,Dx1,Dy1,Du1,Dv1).
del(Item,[Item|List],List).
del(Item,[First|List],[First|List1]):-del(Item,List,List1).