ترغب بنشر مسار تعليمي؟ اضغط هنا

Wadge Degrees of $omega$-Languages of Petri Nets

174   0   0.0 ( 0 )
 نشر من قبل Olivier Finkel
 تاريخ النشر 2017
  مجال البحث الهندسة المعلوماتية
والبحث باللغة English
 تأليف Olivier Finkel




اسأل ChatGPT حول البحث

We prove that $omega$-languages of (non-deterministic) Petri nets and $omega$-languages of (non-deterministic) Turing machines have the same topological complexity: the Borel and Wadge hierarchies of the class of $omega$-languages of (non-deterministic) Petri nets are equal to the Borel and Wadge hierarchies of the class of $omega$-languages of (non-deterministic) Turing machines which also form the class of effective analytic sets. In particular, for each non-null recursive ordinal $alpha < omega_1^{{rm CK}} $ there exist some ${bf Sigma}^0_alpha$-complete and some ${bf Pi}^0_alpha$-complete $omega$-languages of Petri nets, and the supremum of the set of Borel ranks of $omega$-languages of Petri nets is the ordinal $gamma_2^1$, which is strictly greater than the first non-recursive ordinal $omega_1^{{rm CK}}$. We also prove that there are some ${bf Sigma}_1^1$-complete, hence non-Borel, $omega$-languages of Petri nets, and that it is consistent with ZFC that there exist some $omega$-languages of Petri nets which are neither Borel nor ${bf Sigma}_1^1$-complete. This answers the question of the topological complexity of $omega$-languages of (non-deterministic) Petri nets which was left open in [DFR14,FS14].



قيم البحث

اقرأ أيضاً

141 - Olivier Finkel 2007
We show that, from a topological point of view, considering the Borel and the Wadge hierarchies, 1-counter Buchi automata have the same accepting power than Turing machines equipped with a Buchi acceptance condition. In particular, for every non null recursive ordinal alpha, there exist some Sigma^0_alpha-complete and some Pi^0_alpha-complete omega context free languages accepted by 1-counter Buchi automata, and the supremum of the set of Borel ranks of context free omega languages is the ordinal gamma^1_2 which is strictly greater than the first non recursive ordinal. This very surprising result gives answers to questions of H. Lescow and W. Thomas [Logical Specifications of Infinite Computations, In:A Decade of Concurrency, LNCS 803, Springer, 1994, p. 583-621].
We show that there are $Sigma_3^0$-complete languages of infinite words accepted by non-deterministic Petri nets with Buchi acceptance condition, or equivalently by Buchi blind counter automata. This shows that omega-languages accepted by non-determi nistic Petri nets are topologically more complex than those accepted by deterministic Petri nets.
163 - Olivier Finkel 2008
Locally finite omega languages were introduced by Ressayre in [Journal of Symbolic Logic, Volume 53, No. 4, p.1009-1026]. They generalize omega languages accepted by finite automata or defined by monadic second order sentences. We study here closure properties of the family LOC_omega of locally finite omega languages. In particular we show that the class LOC_omega is neither closed under intersection nor under complementation, giving an answer to a question of Ressayre.
119 - Olivier Finkel 2008
We prove in this paper that the length of the Wadge hierarchy of omega context free languages is greater than the Cantor ordinal epsilon_omega, which is the omega-th fixed point of the ordinal exponentiation of base omega. The same result holds for t he conciliating Wadge hierarchy, defined by J. Duparc, of infinitary context free languages, studied by D. Beauquier. We show also that there exist some omega context free languages which are Sigma^0_omega-complete Borel sets, improving previous results on omega context free languages and the Borel hierarchy.
259 - Olivier Finkel 2020
The $omega$-power of a finitary language L over a finite alphabet $Sigma$ is the language of infinite words over $Sigma$ defined by L $infty$ := {w 0 w 1. .. $in$ $Sigma$ $omega$ | $forall$i $in$ $omega$ w i $in$ L}. The $omega$-powers appear very na turally in Theoretical Computer Science in the characterization of several classes of languages of infinite words accepted by various kinds of automata, like B{u}chi automata or B{u}chi pushdown automata. We survey some recent results about the links relating Descriptive Set Theory and $omega$-powers.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا