1 files changed, 12 insertions, 0 deletions
diff --git a/source/program.lux b/source/program.lux
new file mode 100644
index 000000000..6ec9db79e
--- /dev/null
+++ b/source/program.lux
@@ -0,0 +1,12 @@
+(;alias-lux)
+
+(def (filter p xs)
+  (All [a] (-> (-> a Bool) (List a) (List a)))
+  (case xs
+    #;Nil
+    (list)
+
+    (#;Cons [x xs'])
+    (if (p x)
+      (list& x (filter p xs'))
+      (filter p xs'))))