Algorithm for the set of generators of an arbitrary firing count vector in Petri nets

In this paper, an effective method to obtain all nonnegative integer minimal support vectors (U/sub 4/,V/sub 4/) at level 4 for an arbitrary homogeneous/inhomogeneous solution starting from nonnegative rational number minimal support vectors (U/sub 3/,V/sub 3/) at level 3 is proposed. Although V/sub 4/ has been derived from all minimal vectors (U/sub 5/,V/sub 5/) of level 5 which are obtained starting from vectors at level 1, 2, or 3, so far. This proposed method for (U/sub 4/,V/sub 4/) gives us a big shortcut comparing with them. However, it is pointed out that obtaining (U/sub 5/,V/sub 5/) of level 5 from (U/sub 4/,V/sub 4/) of level 4 is not so wise.