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diff --git a/src/elaborate.sml b/src/elaborate.sml
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+(* Copyright (c) 2008, Adam Chlipala
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * - The names of contributors may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *)
+
+structure Elaborate :> ELABORATE = struct
+
+structure L = Laconic
+structure L' = Elab
+structure E = ElabEnv
+structure U = ElabUtil
+
+fun elabKind (k, loc) =
+    case k of
+        L.KType => (L'.KType, loc)
+      | L.KArrow (k1, k2) => (L'.KArrow (elabKind k1, elabKind k2), loc)
+      | L.KName => (L'.KName, loc)
+      | L.KRecord k => (L'.KRecord (elabKind k), loc)
+
+fun elabExplicitness e =
+    case e of
+        L.Explicit => L'.Explicit
+      | L.Implicit => L'.Implicit
+
+fun occursKind r =
+    U.Kind.exists (fn L'.KUnif (_, r') => r = r'
+                    | _ => false)
+
+datatype unify_error =
+         KOccursCheckFailed of L'.kind * L'.kind
+       | KIncompatible of L'.kind * L'.kind
+
+fun unifyError err =
+    case err of
+        KOccursCheckFailed (k1, k2) =>
+        ErrorMsg.errorAt (#2 k1) "Kind occurs check failed"
+      | KIncompatible (k1, k2) =>
+        ErrorMsg.errorAt (#2 k1) "Incompatible kinds"
+
+fun unifyKinds (k1All as (k1, pos)) (k2All as (k2, _)) =
+    let
+        fun err f = unifyError (f (k1All, k2All))
+    in
+        case (k1, k2) of
+            (L'.KType, L'.KType) => ()
+          | (L'.KArrow (d1, r1), L'.KArrow (d2, r2)) =>
+            (unifyKinds d1 d2;
+             unifyKinds r1 r2)
+          | (L'.KName, L'.KName) => ()
+          | (L'.KRecord k1, L'.KRecord k2) => unifyKinds k1 k2
+
+          | (L'.KError, _) => ()
+          | (_, L'.KError) => ()
+
+          | (L'.KUnif (_, ref (SOME k1All)), _) => unifyKinds k1All k2All
+          | (_, L'.KUnif (_, ref (SOME k2All))) => unifyKinds k1All k2All
+
+          | (L'.KUnif (_, r1), L'.KUnif (_, r2)) =>
+            if r1 = r2 then
+                ()
+            else
+                r1 := SOME k2All
+
+          | (L'.KUnif (_, r), _) =>
+            if occursKind r k2All then
+                err KOccursCheckFailed
+            else
+                r := SOME k2All
+          | (_, L'.KUnif (_, r)) =>
+            if occursKind r k1All then
+                err KOccursCheckFailed
+            else
+                r := SOME k1All
+
+          | _ => err KIncompatible
+    end
+
+fun elabFile _ = raise Fail ""
+
+end