--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/expl_util.sig	Thu Jun 19 10:06:59 2008 -0400
@@ -0,0 +1,109 @@
+(* 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_UTIL = sig
+
+structure Kind : sig
+    val mapfold : (Expl.kind', 'state, 'abort) Search.mapfolder
+                  -> (Expl.kind, 'state, 'abort) Search.mapfolder
+    val exists : (Expl.kind' -> bool) -> Expl.kind -> bool
+end
+
+structure Con : sig
+    datatype binder =
+             Rel of string * Expl.kind
+           | Named of string * Expl.kind
+
+    val mapfoldB : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                    con : ('context, Expl.con', 'state, 'abort) Search.mapfolderB,
+                    bind : 'context * binder -> 'context}
+                   -> ('context, Expl.con, 'state, 'abort) Search.mapfolderB
+    val mapfold : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                   con : (Expl.con', 'state, 'abort) Search.mapfolder}
+                  -> (Expl.con, 'state, 'abort) Search.mapfolder
+
+    val mapB : {kind : Expl.kind' -> Expl.kind',
+                con : 'context -> Expl.con' -> Expl.con',
+                bind : 'context * binder -> 'context}
+               -> 'context -> (Expl.con -> Expl.con)
+    val map : {kind : Expl.kind' -> Expl.kind',
+               con : Expl.con' -> Expl.con'}
+              -> Expl.con -> Expl.con
+    val exists : {kind : Expl.kind' -> bool,
+                  con : Expl.con' -> bool} -> Expl.con -> bool
+end
+
+structure Exp : sig
+    datatype binder =
+             RelC of string * Expl.kind
+           | NamedC of string * Expl.kind
+           | RelE of string * Expl.con
+           | NamedE of string * Expl.con
+
+    val mapfoldB : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                    con : ('context, Expl.con', 'state, 'abort) Search.mapfolderB,
+                    exp : ('context, Expl.exp', 'state, 'abort) Search.mapfolderB,
+                    bind : 'context * binder -> 'context}
+                   -> ('context, Expl.exp, 'state, 'abort) Search.mapfolderB
+    val mapfold : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                   con : (Expl.con', 'state, 'abort) Search.mapfolder,
+                   exp : (Expl.exp', 'state, 'abort) Search.mapfolder}
+                  -> (Expl.exp, 'state, 'abort) Search.mapfolder
+    val exists : {kind : Expl.kind' -> bool,
+                  con : Expl.con' -> bool,
+                  exp : Expl.exp' -> bool} -> Expl.exp -> bool
+end
+
+structure Sgn : sig
+    datatype binder =
+             RelC of string * Expl.kind
+           | NamedC of string * Expl.kind
+           | Str of string * Expl.sgn
+
+    val mapfoldB : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                    con : ('context, Expl.con', 'state, 'abort) Search.mapfolderB,
+                    sgn_item : ('context, Expl.sgn_item', 'state, 'abort) Search.mapfolderB,
+                    sgn : ('context, Expl.sgn', 'state, 'abort) Search.mapfolderB,
+                    bind : 'context * binder -> 'context}
+                   -> ('context, Expl.sgn, 'state, 'abort) Search.mapfolderB
+
+
+    val mapfold : {kind : (Expl.kind', 'state, 'abort) Search.mapfolder,
+                   con : (Expl.con', 'state, 'abort) Search.mapfolder,
+                   sgn_item : (Expl.sgn_item', 'state, 'abort) Search.mapfolder,
+                   sgn : (Expl.sgn', 'state, 'abort) Search.mapfolder}
+                  -> (Expl.sgn, 'state, 'abort) Search.mapfolder
+
+    val map : {kind : Expl.kind' -> Expl.kind',
+               con : Expl.con' -> Expl.con',
+               sgn_item : Expl.sgn_item' -> Expl.sgn_item',
+               sgn : Expl.sgn' -> Expl.sgn'}
+              -> Expl.sgn -> Expl.sgn
+
+end
+
+end