Deciding Top-Down Determinism of Regular Tree Languages
نویسندگان
چکیده
It is well known that for a regular tree language it decidable whether or not can be recognized by deterministic top-down automaton (DTA). However, the computational complexity of this problem has been studied. We show given bottom-up decided in quadratic time its DTA. Since there are finite languages cannot DTAs, we also consider unions DTAs and here, definability within automata time.
منابع مشابه
Top-Down Tree Edit-Distance of Regular Tree Languages
We study the edit-distance of regular tree languages. The edit-distance is a metric for measuring the similarity or dissimilarity between two objects, and a regular tree language is a set of trees accepted by a finite-state tree automaton or described by a regular tree grammar. Given two regular tree languages L and R, we define the editdistance d(L,R) between L and R to be the minimum edit-dis...
متن کاملDeciding determinism of unary languages
In this paper, we investigate the complexity of deciding determinism of unary languages. First, we give a method to derive a set of arithmetic progressions from a regular expression E over a unary alphabet, and establish relations between numbers represented by these arithmetic progressions and words in L(E). Next, we define a problem relating to arithmetic progressions and investigate the comp...
متن کاملDeciding the Borel Complexity of Regular Tree Languages
We show that it is decidable whether a given a regular tree language belongs to the class ∆2 of the Borel hierarchy, or equivalently whether the Wadge degree of a regular tree language is countable.
متن کاملDeciding Piecewise Testable Separability for Regular Tree Languages
The piecewise testable separability problem asks, given two input languages, whether there exists a piecewise testable language that contains the first input language and is disjoint from the second. We prove a general characterisation of piecewise testable separability on languages in a well-quasiorder, in terms of ideals of the ordering. This subsumes the known characterisations in the case o...
متن کاملLearning Top-Down Tree Transducers with Regular Domain Inspection
We study the problem of how to learn tree transformations on a given regular tree domain from a finite sample of input-output examples. We assume that the target tree transformation can be defined by a deterministic top-down tree transducer with regular domain inspection (DTopIreg). An rpni style learning algorithm that solves this problem in polynomial time and with polynomially many examples ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Lecture Notes in Computer Science
سال: 2021
ISSN: ['1611-3349', '0302-9743']
DOI: https://doi.org/10.1007/978-3-030-86593-1_24