Now time to make sudoku

sudoku.lispbm

@@ -0,0 +1,13 @@
+(define nums '(1 2 3 4 5 6 7 8 9))
+
+(define valid
+    (lambda (x)
+      (foldr
+       (lambda (y z)
+         (match (filter (lambda (q) (= q y)) nums)
+           (((? r) . nil) (match (filter (lambda (q) (= r q)) x)
+                                 (((? _)) z)
+                                 (_ nil)))
+           (_ nil)))
+       t
+       x)))