val strip_trailing_blanks: string -> string
+ (** Gdome.element of a MathML document whose rendering should be blank. Used
+ * by cicBrowser to render "about:blank" document *)
+val empty_mathml: unit -> Gdome.document
+val empty_boxml: unit -> Gdome.document
+
+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
+ 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)
+
+ (** create a list of directories, building also parents as needed *)
+val mkdirs: string list -> unit
+
+ (** {2 db handling} *)
+val dbd_instance: unit -> Mysql.dbd
+