(* ||M|| This file is part of HELM, an Hypertextual, Electronic ||A|| Library of Mathematics, developed at the Computer Science ||T|| Department, University of Bologna, Italy. ||I|| ||T|| HELM is free software; you can redistribute it and/or ||A|| modify it under the terms of the GNU General Public License \ / version 2 or (at your option) any later version. \ / This software is distributed as is, NO WARRANTY. V_______________________________________________________________ *) type mark = int let mark = ref 0 (* interface functions ******************************************************) let marks () = !mark let new_mark () = incr mark; !mark let null_mark = 0 let string_of_mark i = string_of_int i let clear_marks () = mark := 0