--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/expl_env.sig	Thu Jun 19 10:06:59 2008 -0400
@@ -0,0 +1,67 @@
+(* 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.
+ *)
+
+signature EXPL_ENV = sig
+
+    exception SynUnif
+    val liftConInCon : int -> Expl.con -> Expl.con
+
+    type env
+
+    val empty : env
+    val basis : env
+
+    exception UnboundRel of int
+    exception UnboundNamed of int
+
+    datatype 'a var =
+             NotBound
+           | Rel of int * 'a
+           | Named of int * 'a
+
+    val pushCRel : env -> string -> Expl.kind -> env
+    val lookupCRel : env -> int -> string * Expl.kind
+
+    val pushCNamed : env -> string -> int -> Expl.kind -> Expl.con option -> env
+    val lookupCNamed : env -> int -> string * Expl.kind * Expl.con option
+
+    val pushERel : env -> string -> Expl.con -> env
+    val lookupERel : env -> int -> string * Expl.con
+
+    val pushENamed : env -> string -> int -> Expl.con -> env
+    val lookupENamed : env -> int -> string * Expl.con
+
+    val pushSgnNamed : env -> string -> int -> Expl.sgn -> env
+    val lookupSgnNamed : env -> int -> string * Expl.sgn
+
+    val pushStrNamed : env -> string -> int -> Expl.sgn -> env
+    val lookupStrNamed : env -> int -> string * Expl.sgn
+
+    val declBinds : env -> Expl.decl -> env
+    val sgiBinds : env -> Expl.sgn_item -> env
+
+end