In this paper, we present a further development of this approach. We adopt Contejean-Devie's algorithm for solving systems of linear constraints over the natural numbers domain and refine it, by taking advantage of the specific properties of systems of inear constraints to be solved. The essence of the proposed modifications is to transfer the information about causality and conflicts between the events involved in an unfolding, into a relationship between the corresponding integer variables in the system of linear constraints.
Experimental results demonstrate that the new technique achieves significant speedups.