Alternating Automata. The Weak Monadic Theory of the Tree, and its Complexity
نویسندگان
چکیده
منابع مشابه
Alternating Automata, the Weak Monadic Theory of Trees and its Complexity
Beginning with the fundamental article of Chandra et al. [2], the notation of alternation has clarified several results concerning the complexity of logical theories. Muller and Schupp [9] extended the idea of alternation to automata working on trees. Although such automata are a generalization of Rabin’s model [12] of nondeterministic automata working on infinite trees, complementation and, th...
متن کاملContainment of Monadic Datalog Programs via Bounded Clique-Width
Containment of monadic datalog programs over data trees (labelled trees with an equivalence relation) is undecidable. Recently, decidability was shown for two incomparable fragments: downward programs, which never move up from visited tree nodes, and linear childonly programs, which have at most one intensional predicate per rule and do not use descendant relation. As di erent as the fragments ...
متن کاملDeciding the weak definability of Büchi definable tree languages
Weakly definable languages of infinite trees are an expressive subclass of regular tree languages definable in terms of weak monadic second-order logic, or equivalently weak alternating automata. Our main result is that given a Büchi automaton, it is decidable whether the language is weakly definable. We also show that given a parity automaton, it is decidable whether the language is recognizab...
متن کاملAlternating Regular Tree Grammars in the Framework of Lattice-Valued Logic
In this paper, two different ways of introducing alternation for lattice-valued (referred to as {L}valued) regular tree grammars and {L}valued top-down tree automata are compared. One is the way which defines the alternating regular tree grammar, i.e., alternation is governed by the non-terminals of the grammar and the other is the way which combines state with alternation. The first way is ta...
متن کاملMultidimensional fuzzy finite tree automata
This paper introduces the notion of multidimensional fuzzy finite tree automata (MFFTA) and investigates its closure properties from the area of automata and language theory. MFFTA are a superclass of fuzzy tree automata whose behavior is generalized to adapt to multidimensional fuzzy sets. An MFFTA recognizes a multidimensional fuzzy tree language which is a regular tree language so that for e...
متن کامل