43 research outputs found
Determinacy and rewriting of functional topâdown and MSO tree transformations
A query is determined by a view, if the result of the query can be reconstructed from the result of the view. We consider the problem of deciding for two given (functional) tree transformations, whether one is determined by the other. If the view transformation is induced by a tree transducer that may copy, then determinacy is undecidable. For a large class of noncopying views, namely compositions of extended linear topâdown tree transducers, we show that determinacy is decidable, where queries are either deterministic topâdown tree transducers (with regular look-ahead) or deterministic MSO tree transducers. We also show that if a query is determined by a view, then it can be rewritten into a query that works over the view and is in the same class of transducers as the query. The proof relies on the decidability of equivalence for the considered classes of queries, and on their composition closure
Node Query Preservation for Deterministic Linear Top-Down Tree Transducers
This paper discusses the decidability of node query preservation problems for
XML document transformations. We assume a transformation given by a
deterministic linear top-down data tree transducer (abbreviated as DLT^V) and
an n-ary query based on runs of a tree automaton. We say that a DLT^V Tr
strongly preserves a query Q if there is a query Q' such that for every
document t, the answer set of Q' for Tr(t) is equal to the answer set of Q for
t. Also we say that Tr weakly preserves Q if there is a query Q' such that for
every t_d in the range of Tr, the answer set of Q' for t_d is equal to the
union of the answer set of Q for t such that t_d = Tr(t). We show that the weak
preservation problem is coNP-complete and the strong preservation problem is in
2-EXPTIME.Comment: In Proceedings TTATT 2013, arXiv:1311.505
Tree Transducers and Formal Methods (Dagstuhl Seminar 13192)
The aim of this Dagstuhl Seminar was to bring together researchers from various research areas related to the theory and application of tree transducers. Recently, interest in tree transducers has been revived due to surprising new applications in areas such as XML databases, security verification, programming language theory, and linguistics. This seminar therefore aimed to inspire the exchange of theoretical results and information regarding the practical requirements related to tree transducers
Decision Problems of Tree Transducers with Origin - Emmanuel Filiot
International audienc
Relational semantics of linear logic and higher-order model-checking
In this article, we develop a new and somewhat unexpected connection between
higher-order model-checking and linear logic. Our starting point is the
observation that once embedded in the relational semantics of linear logic, the
Church encoding of any higher-order recursion scheme (HORS) comes together with
a dual Church encoding of an alternating tree automata (ATA) of the same
signature. Moreover, the interaction between the relational interpretations of
the HORS and of the ATA identifies the set of accepting states of the tree
automaton against the infinite tree generated by the recursion scheme. We show
how to extend this result to alternating parity automata (APT) by introducing a
parametric version of the exponential modality of linear logic, capturing the
formal properties of colors (or priorities) in higher-order model-checking. We
show in particular how to reunderstand in this way the type-theoretic approach
to higher-order model-checking developed by Kobayashi and Ong. We briefly
explain in the end of the paper how his analysis driven by linear logic results
in a new and purely semantic proof of decidability of the formulas of the
monadic second-order logic for higher-order recursion schemes.Comment: 24 pages. Submitte
Playing with Trees and Logic
This document proposes an overview of my research sinc
Equivalence Problems for Tree Transducers: A Brief Survey
The decidability of equivalence for three important classes of tree
transducers is discussed. Each class can be obtained as a natural restriction
of deterministic macro tree transducers (MTTs): (1) no context parameters,
i.e., top-down tree transducers, (2) linear size increase, i.e., MSO definable
tree transducers, and (3) monadic input and output ranked alphabets. For the
full class of MTTs, decidability of equivalence remains a long-standing open
problem.Comment: In Proceedings AFL 2014, arXiv:1405.527