1 (defun cont-frac (n d k)
2   (labels (
3 	   (frac (i)
4 		 (/ (funcall n i)
5 		    (+ (funcall d i)
6 		       (if (= i k)
7 			   0
8 			 (frac (1+ i)))))))
9 	  (frac 1)))
10 
11 (defun cont-frac-iter (n d k)
12   (labels (
13 	   (frac-iter (i result)
14 		      (if (= i 0)
15 			  result
16 			(frac-iter
17 			 (1- i)
18 			 (/ (funcall n i)
19 			    (+ (funcall d i) result))))))
20 	  (frac-iter k 0)))