From d30a5ee04dd437f969fca7ad2b3faee7ed324562 Mon Sep 17 00:00:00 2001
From: Adam Chlipala <adam@chlipala.net>
Date: Tue, 23 Dec 2014 14:41:23 -0500
Subject: List.mem

---
 lib/ur/list.ur | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'lib/ur/list.ur')

diff --git a/lib/ur/list.ur b/lib/ur/list.ur
index cbb4faf2..11895884 100644
--- a/lib/ur/list.ur
+++ b/lib/ur/list.ur
@@ -216,6 +216,16 @@ fun foldlMap [a] [b] [c] f =
         fold []
     end
 
+fun mem [a] (_ : eq a) (x : a) =
+    let
+        fun mm ls =
+            case ls of
+                [] => False
+              | y :: ls => y = x || mm ls
+    in
+        mm
+    end
+
 fun find [a] f =
     let
         fun find' ls =
-- 
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