  Detectability describes the property of a system whose current and the
subsequent states can be uniquely determined after a finite number of
observations. In this paper, we developed a novel approach to verifying strong
detectability and periodically strong detectability of bounded labeled Petri
nets. Our approach is based on the analysis of the basis reachability graph of
a special Petri net, called Verifier Net, that is built from the Petri net
model of the given system. Without computing the whole reachability space and
without enumerating all the markings, the proposed approaches are more
efficient.
