Model Verification Through Dependency Graphs

Dependency graphs, as introduced more than 20 years ago by Liu and Smolka, are oriented graphs with hyperedges that connect nodes with sets of target nodes in order to represent causal dependencies in the graph. Numerous verification problems can be reduced into the problem of computing a minimum or maximum fixed-point assignment on dependency graphs. In the original definition, assignments link each node with a Boolean value, however, in the recent work the assignment domains have been extended to more general setting, even including infinite domains. We present an overview of the recent results on extensions of dependency graphs in order to deal with verification of quantitative, probabilistic and timed systems.