21 Apr 98:	bug in covergraph-computation fixed
11 Nov 98:	version 2.2 released (for Sun-OS 4, Solaris, Linux, Windows-32)
		state representation for timed-nets changed, minor bug-fixes
19 Apr 99:	bug in scc-computation fixed
		manual for version 2.2 released 
 1 Jul 99:      bug in test for structural boundedness fixed		 
                version 2.2 patch level 1 released
 4 Aug 99:	bug in symmetry-computation fixed (only eft/lft)
 		bug in path-computation fixed
                version 2.2 patch level 2 released
02 Feb 00:	bug in name-reading/writing fixed
		bug in conclusions: Fp=0 or pF=0 implies not SMD
                version 2.2 patch level 3 released		
20 Apr 00:	bug in formula-reading fixed (only Windows)
		command line switch -silent or -cmd:
			don't ask same procedure, save net, command, rename ...	
			and load COMMAND.ina automatically (if available)
		version 2.2 patch level 4 released
21 Aug 00:	bug in CTL model checker fixed (AG and terminal states)
		bug in file-reading fixed
		version 2.2 patch level 5 released
23 Mar 01:	bug in maximal step computation fixed
		bug in computation of invariants fixed
		version 2.2 patch level 6 released
31 Jul 03:	bug in net output fixed
		bug in priorities fixed
		priorities for duration timed nets implemented
		path computation rearranged: dead state elimination
          	final version 2.2final released