Corrections to “On the Decidability and Complexity of Diagnosability for Labeled Petri Nets” [Nov 17 5931-5938]

This note aims to correct a complexity result in our paper that investigates the verification of diagnosability for unbounded Petri nets. The main result of [1] is Theorem IV.1, which shows that the diagnosability verification problem can be reduced to a Petri net model checking problem called Yen's problem [2]. This main reduction is still correct. However, it was pointed out by Atig and Habermehl [3] that Yen's original complexity result is not completely correct 1. Specifically, they showed that: (i) in general, Yen's problem is still decidable, but it is as hard as the reachability problem, which corrects the original EXPSPACE-completeness claim in [2]; and (ii) for a special case called the increasing fragment, Yen's problem can be solved in EXPSPACE.