(defun partitionNum (a b)
  (if (= b 1)
      (list (list a))
    (let ((x 0) (l '()))
      (while (<= x a)
	(progn
	  (setq l
		(append 
		 l
		 (list-of (append (list (- a x)) y)
			  (y in (partitionNum x (- b 1))))))
	  (setq x (+ x 1))))
      l)))
(print (partitionNum 5 3))