Refining Undecidability Border of Weak Bisimilarity.
|Title in English||Refining Undecidability Border of Weak Bisimilarity|
|Year of publication||2006|
|Type||Article in Proceedings|
|Conference||Proceedings of the 7th International Workshop on Verification of Infinite-State Systems (INFINITY'05)|
|MU Faculty or unit|
|Keywords||process rewrite systems; state extension; infinite-state; decidability; weak bisimilarity|
|Description||Weak bisimilarity is one of the most studied behavioural equivalences. This equivalence is undecidable for pushdown processes (PDA), process algebras (PA), and multiset automata (MSA, also known as parallel pushdown processes, PPDA). Its decidability is an open question for basic process algebras (BPA) and basic parallel processes (BPP). We move the undecidability border towards these classes by showing that the equivalence remains undecidable for weakly extended versions of BPA and BPP. In fact, we show that the weak bisimulation equivalence problem is undecidable even for normed subclasses of BPA and BPP extended with a finite constraint system.|