Paper Info
Title
A Note on Monitors and Büchi automata.
Abstract
When a property needs to be checked against an unknown or very complex system, classical exploration techniques like model-checking are not applicable anymore. Sometimes a﾿monitor can be used, that checks a given property on the underlying system at runtime. A monitor for a property L is a deterministic finite automaton $$\\mathcal {M}_L$$ that after each finite execution tells whether 1 every possible extension of the execution is in L, or 2 every possible extension is in the complement of L, or neither 1 nor 2 holds. Moreover, L being monitorable means that it is always possible that in some future the monitor reaches 1 or 2. Classical examples for monitorable properties are safety and cosafety properties. On the other hand, deterministic liveness properties like \"infinitely many a's\" are not monitorable. We discuss various monitor constructions with a focus on deterministic $$\\omega $$-regular languages. We locate a proper subclass of deterministic $$\\omega $$-regular languages but also strictly larger than the subclass of languages which are deterministic and codeterministic; and for this subclass there exist canonical monitors which also accept the language itself. We also address the problem to decide monitorability in comparison with deciding liveness. The state of the art is as follows. Given a Büchi automaton, it is PSPACE-complete to decide liveness or monitorability. Given an LTL formula, deciding liveness becomes EXPSPACE-complete, but the complexity to decide monitorability remains open.
Year
DOI
Venue
2015
10.1007/978-3-319-25150-9_3
International Colloquium on Theoretical Aspects of Computing
DocType
Volume
ISSN
Conference
abs/1507.01020
0302-9743
Citations 
PageRank 
References 
3
0.39
11
Authors
3
Name
Order
Citations
PageRank
Volker Diekert170267.46
Anca Muscholl2117974.92
Igor Walukiewicz3123990.24