Way simpler

sudoku.lispbm

@@ -1,15 +1,12 @@
 (define nums '(1 2 3 4 5 6 7 8 9))
 
-(define valid
-    (lambda (x)
-      (foldr
-       (lambda (y z)
-         (match y
-            (nil z)
-            (_ (match (filter (lambda (q) (= q y)) nums)
-                (((? r) . nil) (match (filter (lambda (q) (eq r q)) x)
-                                (((? _)) z)
-                                (_ nil)))
-                (_ nil)))))
-       t
-       x)))
+(defun amount (x y)
+  (foldr (lambda (z q) (if (eq x z) (+ q 1) q)) 0 y))
+
+(defun valid (x)
+      (if (= 9 (length x))
+          (foldr (lambda (y z) (if (<= y 1) z nil))
+                 t
+                 (map (lambda (y) (amount y x)) nums))
+          nil
+      ))