The Decidability of the Generalized Confluence Problem for Context-Free Languages

نویسنده

  • Lucian Ilie
چکیده

A language L is con uent with respect to a given quasi order on if, for any x; y 2 L, there is z 2 L such that x z and y z. L is con uent with respect to in generalized sense if it is a nite union of languages conuent with respect to . We investigate in this paper the decidability of the generalized con uence problem with respect to the pre x partial order and the factor partial order for context-free languages, thus generalizing previuos results concerning the decidability of the ordinary con uence problem.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Decidability of Context Logic

We consider the problem of decidability for Context Logic for sequences, ranked trees and unranked trees. We show how to translate quantifier-free formulae into finite automata that accept just the sequences or trees which satisfy the formulae. Satisfiability is thereby reduced to the language emptiness problem for finite automata, which is simply a question of reachability. This reduction show...

متن کامل

On lengths of words in context-free languages

We consider slender languages, that is, languages for which the number of words of the same length is bounded from above by a constant. We prove that the slenderness problem is decidable for context-free languages and that the maximal number of words of the same length in a given context-free language is computable. Some e ective representations of slender context-free languages, as well as oth...

متن کامل

Decidability of fairness for context-free languages

Trajectories are a powerful tool for de ning the parallel composition of words and languages [8]. One can introduce natural fairness conditions for the shu e operation de ned by a trajectory. It is fairly easy to see that the n-fairness property is decidable for a given context-free language and integer n 1 but the decidability of the corresponding uniform fairness problem remained open. Here w...

متن کامل

Reflection From Free Surface of a Rotating Generalized Thermo-Piezoelectric Solid Half Space

The analysis of rotational effect on the characteristics of plane waves propagating in a half space of generalized thermo-piezoelectric medium is presented in context of linear theory of thermo-piezoelectricity including Coriolis and centrifugal forces. The governing equations for a rotating generalized thermo-piezoelectric medium are formulated and solved for plane wave solutions to show the p...

متن کامل

On the Confluence of Trace Rewriting Systems

In [NO88], a particular trace monoid M is constructed such that for the class of length–reducing trace rewriting systems over M , confluence is undecidable. In this paper, we show that this result holds for every trace monoid, which is neither free nor free commutative. Furthermore we will present a new criterion for trace rewriting systems that implies decidability of confluence.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1997