In this paper, we study supervisory control of a class of discrete event systems with simultaneous event occurrences, which we call concurrent discrete event systems. The behavior of the system is described by a language over the simultaneous event set. We introduce a notion of concurrent well-posedness of languages. We then prove that Lm(G)-closure, controllability, and concurrent well-posedness
... [Show full abstract] of a specification language are necessary and sufficient conditions for the existence of a non-blocking supervisor. We address the computational complexity for verifying the existence conditions.