A-M baby

Task/Fibonacci-sequence/ACL2/fibonacci-sequence.acl2

@@ -0,0 +1,17 @@
+(defun fast-fib-r (n a b)
+   (if (or (zp n) (zp (1- n)))
+       b
+       (fast-fib-r (1- n) b (+ a b))))
+
+(defun fast-fib (n)
+   (fast-fib-r n 1 1))
+
+(defun first-fibs-r (n i)
+   (declare (xargs :measure (nfix (- n i))))
+   (if (zp (- n i))
+       nil
+       (cons (fast-fib i)
+             (first-fibs-r n (1+ i)))))
+
+(defun first-fibs (n)
+   (first-fibs-r n 0))