--- /dev/null
+(* Copyright (C) 2004-2005, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+val absolute_path: string -> string
+
+ (** @return true if file is a (textual) proof script *)
+val is_proof_script: string -> bool
+
+ (** @return true if file is a (binary) proof object *)
+val is_proof_object: string -> bool
+
+ (** given a phrase, if it doesn't end with BuildTimeConf.phrase_sep, append
+ * it *)
+val append_phrase_sep: string -> string
+
+val normalize_dir: string -> string (** add trailing "/" if missing *)
+val strip_suffix: suffix:string -> string -> string
+
+ (** @return tl tail of a list starting at a given element
+ * @param eq equality to be used, defaults to physical equality (==)
+ * @raise Not_found *)
+val list_tl_at: ?equality:('a -> 'a -> bool) -> 'a -> 'a list -> 'a list
+
+exception History_failure
+
+type 'a memento
+
+class type ['a] history =
+ object ('b)
+ method add : 'a -> unit
+ method next : 'a (** @raise History_failure *)
+ method previous : 'a (** @raise History_failure *)
+ method load: 'a memento -> unit
+ method save: 'a memento
+ method is_begin: bool
+ method is_end: bool
+ end
+
+ (** shell like history: new items added at the end of the history
+ * @param size maximum history size *)
+class shell_history : int -> [string] history
+
+ (** browser like history: new items added at the current point of the history
+ * @param size maximum history size
+ * @param first element in history (this history is never empty) *)
+class ['a] browser_history: ?memento:'a memento -> int -> 'a -> ['a] history
+
+ (** create a singleton from a given function. Given function is invoked the
+ * first time it gets called. Next invocation will return first value *)
+val singleton: (unit -> 'a) -> (unit -> 'a)
+
+ (** given the base name of an image, returns its full path *)
+val image_path: string -> string