aa bb cc xx yy xx yy xx yy ff gg hh ff gg gg hh


*** OK ***
cc & cc                     Ok { (6, 7) }
xx & xx                     Ok { (9, 10) (15, 16) (21, 22) }
xx <> xx                    Ok { (9, 16) (15, 22) }
hh & gg                     Ok { (30, 34) (33, 40) (42, 46) }
yy <> (yy <> yy)            Ok { (12, 25) }
(yy <> yy) <> yy            Ok { (12, 25) }
gg < (gg <> gg)             Ok { (30, 31) (39, 40) (42, 43) }
(xx <> yy) < ((xx <> yy) <> (xx <> yy))
                            Ok { (9, 13) (15, 19) (21, 25) }
                            Eh oui, le dernier est a ne pas oublier car
                            il est bien inclu dans l'intervalle 18 - 25 !
yy < (xx <> xx)             Ok { (12, 13) (18, 19) }
(xx <> yy) < (cc & yy)      Ok { (9, 13) }
xx < (yy <> (yy <> yy))     Ok { (15, 16) (21, 22) }
(gg | hh) | (gg <> hh)      Ok { (30, 31) (33, 34) (39, 40) (42, 43) (45, 46) }
xx < (foo <> bar)           Ok { }
