bookmove(A, B) :-
	books_moved(A, A0),
	list_rotated(A0, B).

books_moved(A, B) :-
	list_rotated(A, A0),
	append(Left, Taken, A0),
	list_rotated(Left, LeftRot),
	append(Taken, LeftRot, B).

list_rotated(A, B) :-
	length(A, Len),
	N0 is Len - 1,
	between(0, N0, N),
	list_n_rotated(A, N, B).

list_n_rotated(A, 0, A).
list_n_rotated(A, N, B) :-
	N > 0,
	[X|Xs] = A,
	append(Xs, [X], A0),
	N0 is N - 1,
	list_n_rotated(A0, N0, B).