A compositional approach for verifying generalised nonblocking

Abstract

Abstract-This paper proposes a compositional approach to verify the generalised nonblocking property of discrete-event systems. Generalised nonblocking is introduced in [1] to overcome weaknesses of the standard nonblocking check in discreteevent systems and increase the scope of liveness properties that can be handled. This paper addresses the question of how generalised nonblocking can be verified efficiently. The explicit construction of the complete state space is avoided by first composing and simplifying individual components in ways that preserve generalised nonblocking. The paper extends and generalises previous results about compositional verification of standard nonblocking and lists a new set of computationally feasible abstraction rules for standard and generalised nonblocking.

A Compositional Approach for Verifying Hierarchical Interface-Based Supervisory Control

“…These properties can be checked efficiently using methods for compositional verification of safety properties such as (Brandin et al, 2004;Ware and Malik, 2008). LDLWNB Property II is a standard nonblocking property, which can be checked directly using the compositional approach for standard nonblocking in (Flordal and Malik, 2009), or by converting the property into generalized nonblocking (Malik and Leduc, 2008) and using compositional verification of generalized nonblocking (Malik and Leduc, 2009). …”

“…This inspired the authors to come up with the generalized nonblocking condition, introduced in (Malik and Leduc, 2008). They then extended the compositional verification results for standard nonblocking to this new setting in (Malik and Leduc, 2009). …”

“…We then use our compositional approach for generalized nonblocking (Malik and Leduc, 2009) to check these conditions. In essence, we perform a hybrid hierarchical-compositional verification.…”

“…Most of the HISC conditions can be verified efficiently using existing methods for compositional verification, but a few are more challenging. This paper shows how these more challenging conditions can be expressed equivalently as generalized nonblocking problems, so the compositional approach for generalized nonblocking developed by the authors in (Malik and Leduc, 2009) is applicable. This makes all the HISC conditions amenable for compositional verification, considerably increasing the size of systems that can be handled using the framework.…”

Hierarchical Interface-Based Supervisory Control Using the Conflict Preorder

“…The conflict preorder can be checked by an exponential algorithm (Ware and Malik, 2011). For improved performance, polynomial abstraction algorithms (Flordal and Malik, 2009;Malik and Leduc, 2009) can replace the subsystem by a conflict equivalent abstraction using only the interface events. Then the smaller abstraction can be compared to the interface by the conflict preorder algorithm.…”