GENERAL REMARK: We remark here that, to reduce the computational complexity and the clarty of many methods called by this program, it would have been wiser to consider 2 MT class (or more) in a single graph and not, as it is done here, in 2 different graphs which are associated. TO BE MODIFIED IN PRIORITY
Note that the time delay information is not included in the graph at format 2 directly, but is included in the standard format. Thus, this input has to be removed and a procedure for reading the graph at the standard format has to replace the actual one. TO BE MODIFIED!!