True Concurrency Can Be Easy

Net bisimilarity is a behavioral equivalence for finite Petri nets, which is equivalent to structure-preserving bisimilarity and causal-net bisimilarity, but with a much simpler definition, which is a smooth generalization of the definition of standard bisimilarity on Labeled Transition Systems. We show that it can be characterized logically by means of a suitable modal logic, called NML (acronym of net modal logic): two markings are net bisimilar if and only if they satisfy the same NML formulae