A gap property of deterministic tree languages
نویسندگان
چکیده
منابع مشابه
A gap property of deterministic tree languages
We show that a tree language recognized by a deterministic parity automaton is either hard for the co–Büchi level and therefore cannot be recognized by a weak alternating automaton, or is on a very low level in the hierarchy of weak alternating automata. A topological counterpart of this property is that a deterministic tree language is either Π 1 complete (and hence non Borel), or it is on the...
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We provide a complete description of the Wadge hierarchy for deterministically recognisable sets of infinite trees. In particular we give an elementary procedure to decide if one deterministic tree language is continuously reducible to another. This extends Wagner’s results on the hierarchy of ω-regular languages of words to the case of trees.
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The composition of total deterministic macro tree transducers gives rise to a proper hierarchy with respect to their output string languages (these are the languages obtained by taking the yields of the output trees). There is a language not in this hierarchy which can be generated by a (quite restricted) nondeterministic string transducer, namely, a two-way generalized sequential machine. Simi...
متن کاملDeterministic Left to Right Parsing of Tree Adjoining Languages
We define a set of deterministic bottom-up left to right parsers which analyze a subset of Tree Adjoining Languages. The LR parsing strategy for Context Free Grammars is extended to Tree Adjoining Grammars (TAGs). We use a machine, called Bottom-up Embedtied Push Down Automaton (BEPDA), that recognizes in a bottom-up fashion the set of Tree Adjoining Languages (and exactly this se0. Each parser...
متن کاملOn Deciding Topological Classes of Deterministic Tree Languages
It has been proved by Niwiński and Walukiewicz that a deterministic tree language is either Π 1 -complete or it is on the level Π 0 3 of the Borel hierarchy, and that it can be decided effectively which of the two takes place. In this paper we show how to decide if the language recognized by a given deterministic tree automaton is on the Π 2 , the Σ 2 , or the Σ 0 3 level. Together with the pre...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2003
ISSN: 0304-3975
DOI: 10.1016/s0304-3975(02)00452-8