(DE QTAK (U) 
       (IF (= (CAR U) 1) (CADR U)
	   ((LAMBDA (W) ((LAMBDA (X Y Z) 
			       (IF
				(GE Y X) Y
				(QTAK (LIST 2
					       (LIST 2
						     (LIST 1
							   (1- X))
						     (LIST 1 Y)
 						     Z)
					       (LIST 2
						     (LIST 1
							   (1- Y))
						     Z
						     (LIST 1 X))
					       (LIST 3
						     (LIST 1 X)
						     (LIST 1 Y)
						     Z)))))
			      (1 W)
			      (2 W)
			      (3 W)))
		 (IF (= (1 U) 2)
			(LIST (QTAK (2 U))
			      (QTAK (3 U))
			      (4 U))
		        (LIST (1- (QTAK (4 U)))
				(QTAK (2 U))
				(3 U)))))))) 


(DE QQTAK (X Z) (QTAK (LIST 2 (LIST 1 X) (LIST 1 0) (LIST 1 Z))))