(* *)
(***********************************************************************)
+(*
+ Time-stamp: <Last modified on 2013-01-30 19:08:11 CET by Kim Nguyen>
+*)
+
open Format
exception InvalidUtf8Codepoint of int
let right_arrow = "→"
let left_arrow = "←"
let epsilon = "ϵ"
+let big_sigma = "∑"
let cap = "∩"
let cup = "∪"
let lnot = "¬"