--- a/src/compiler.sig	Thu Jul 17 12:40:21 2008 -0400
+++ b/src/compiler.sig	Thu Jul 17 12:59:52 2008 -0400
@@ -49,6 +49,7 @@
     val monoize : job -> Mono.file option
     val mono_opt' : job -> Mono.file option
     val untangle : job -> Mono.file option
+    val mono_reduce : job -> Mono.file option
     val mono_opt : job -> Mono.file option
     val cjrize : job -> Cjr.file option
 
@@ -63,6 +64,7 @@
     val testMonoize : job -> unit
     val testMono_opt' : job -> unit
     val testUntangle : job -> unit
+    val testMono_reduce : job -> unit
     val testMono_opt : job -> unit
     val testCjrize : job -> unit
 

--- a/src/compiler.sml	Thu Jul 17 12:40:21 2008 -0400
+++ b/src/compiler.sml	Thu Jul 17 12:59:52 2008 -0400
@@ -250,8 +250,17 @@
         else
             SOME (Untangle.untangle file)
 
+fun mono_reduce job =
+    case untangle job of
+        NONE => NONE
+      | SOME file =>
+        if ErrorMsg.anyErrors () then
+            NONE
+        else
+            SOME (MonoReduce.reduce file)
+
 fun mono_opt job =
-    case untangle job of
+    case mono_reduce job of
         NONE => NONE
       | SOME file =>
         if ErrorMsg.anyErrors () then
@@ -366,6 +375,15 @@
     handle MonoEnv.UnboundNamed n =>
            print ("Unbound named " ^ Int.toString n ^ "\n")
 
+fun testMono_reduce job =
+    (case mono_reduce job of
+         NONE => print "Failed\n"
+       | SOME file =>
+         (Print.print (MonoPrint.p_file MonoEnv.empty file);
+          print "\n"))
+    handle MonoEnv.UnboundNamed n =>
+           print ("Unbound named " ^ Int.toString n ^ "\n")
+
 fun testMono_opt job =
     (case mono_opt job of
          NONE => print "Failed\n"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mono_reduce.sig	Thu Jul 17 12:59:52 2008 -0400
@@ -0,0 +1,34 @@
+(* 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.
+ *)
+
+(* Simplify a Mono program algebraically *)
+
+signature MONO_REDUCE = sig
+
+    val reduce : Mono.file -> Mono.file
+    
+end

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mono_reduce.sml	Thu Jul 17 12:59:52 2008 -0400
@@ -0,0 +1,89 @@
+(* 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.
+ *)
+
+(* Simplify a Mono program algebraically *)
+
+structure MonoReduce :> MONO_REDUCE = struct
+
+open Mono
+
+structure E = MonoEnv
+structure U = MonoUtil
+
+val liftExpInExp =
+    U.Exp.mapB {typ = fn t => t,
+                exp = fn bound => fn e =>
+                                     case e of
+                                         ERel xn =>
+                                         if xn < bound then
+                                             e
+                                         else
+                                             ERel (xn + 1)
+                                       | _ => e,
+                bind = fn (bound, U.Exp.RelE _) => bound + 1
+                        | (bound, _) => bound}
+
+val subExpInExp =
+    U.Exp.mapB {typ = fn t => t,
+                exp = fn (xn, rep) => fn e =>
+                                  case e of
+                                      ERel xn' =>
+                                      (case Int.compare (xn', xn) of
+                                           EQUAL => #1 rep
+                                         | GREATER=> ERel (xn' - 1)
+                                         | LESS => e)
+                                    | _ => e,
+                bind = fn ((xn, rep), U.Exp.RelE _) => (xn+1, liftExpInExp 0 rep)
+                        | (ctx, _) => ctx}
+
+fun bind (env, b) =
+    case b of
+        U.Decl.NamedT (x, n, co) => E.pushTNamed env x n co
+      | U.Decl.RelE (x, t) => E.pushERel env x t
+      | U.Decl.NamedE (x, n, t, eo, s) => E.pushENamed env x n t eo s
+
+fun typ c = c
+
+fun exp env e =
+    case e of
+        ENamed n =>
+        (case E.lookupENamed env n of
+             (_, _, SOME e', _) => #1 e'
+           | _ => e)
+
+      | EApp ((EAbs (_, _, _, e1), loc), e2) =>
+        #1 (reduceExp env (subExpInExp (0, e2) e1))
+
+      | _ => e
+
+and reduceExp env = U.Exp.mapB {typ = typ, exp = exp, bind = bind} env
+
+fun decl env d = d
+
+val reduce = U.File.mapB {typ = typ, exp = exp, decl = decl, bind = bind} E.empty
+
+end

--- a/src/reduce.sml	Thu Jul 17 12:40:21 2008 -0400
+++ b/src/reduce.sml	Thu Jul 17 12:59:52 2008 -0400
@@ -171,6 +171,6 @@
 
 fun decl env d = d
 
-val reduce = U.File.mapB {kind = kind, con = con, exp = exp, decl = decl, bind = bind} CoreEnv.empty
+val reduce = U.File.mapB {kind = kind, con = con, exp = exp, decl = decl, bind = bind} E.empty
 
 end

--- a/src/sources	Thu Jul 17 12:40:21 2008 -0400
+++ b/src/sources	Thu Jul 17 12:59:52 2008 -0400
@@ -78,9 +78,6 @@
 tag.sig
 tag.sml
 
-untangle.sig
-untangle.sml
-
 mono.sml
 
 mono_util.sig
@@ -98,6 +95,12 @@
 mono_opt.sig
 mono_opt.sml
 
+untangle.sig
+untangle.sml
+
+mono_reduce.sig
+mono_reduce.sml
+
 cjr.sml
 
 cjr_env.sig