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How to Remove the Look-Ahead of Top-Down Tree Transducers [chapter]

Joost Engelfriet, Sebastian Maneth, Helmut Seidl
2014 Lecture Notes in Computer Science  
For a top-down tree transducer with regular look-ahead we introduce the notion of difference bound, which is a number bounding the difference in output height for any two look-ahead states of the transducer  ...  We present an algorithm that, for a given transducer with a known difference bound, decides whether it is equivalent to a transducer without regular look-ahead, and constructs such a transducer if the  ...  In general, is there a method to determine for a given top-down tree transducer with look-ahead (dtla), whether or not there is an equivalent top-down tree transducer without look-ahead (dtop)?  ... 
doi:10.1007/978-3-319-09698-8_10 fatcat:cutdwm5izvcahe2efwobcqlefe

Equivalence Problems for Tree Transducers: A Brief Survey

Sebastian Maneth
2014 Electronic Proceedings in Theoretical Computer Science  
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  ...  The decidability of equivalence for three important classes of tree transducers is discussed.  ...  Top-down Tree Transducers with Regular Look-Ahead.  ... 
doi:10.4204/eptcs.151.5 fatcat:bso3z5x5tjgy5fnx5anekyudei

A Survey on Decidable Equivalence Problems for Tree Transducers

Sebastian Maneth
2015 International Journal of Foundations of Computer Science  
controlled by input storage). (2) In terms of a top-down tree transducer, the state calls of the transducer can appear in a nested way (similar to the nesting of nonterminals in the productions of context-free  ...  Top-down tree transducers generalize to trees the finite state (string) transducers (also known as "generalized sequential machines", or gsms, see [47, 9] ).  ...  Acknowledgements I wish to thank Joost Engelfriet and the anonymous referee for many helpful comments on a previous version of this paper.  ... 
doi:10.1142/s0129054115400134 fatcat:5wxybcc6xjbvdg43rgst5c4r5a

The Power of Extended Top-Down Tree Transducers

Andreas Maletti, Jonathan Graehl, Mark Hopkins, Kevin Knight
2009 SIAM journal on computing (Print)  
Their main properties are identified and their relation to classical top-down tree transducers is exactly characterized.  ...  In addition, it is shown that most interesting classes of transformations computed by extended top-down tree transducers are not closed under composition.  ...  In Sect. 3, we present an example of an extended top-down tree transducer and highlight the short-comings of top-down tree transducers.  ... 
doi:10.1137/070699160 fatcat:dvmzpcpei5a2rnc3wy2rw2czn4

When Is a Bottom-Up Deterministic Tree Translation Top-Down Deterministic?

Sebastian Maneth, Helmut Seidl, Emanuela Merelli, Anuj Dawar, Artur Czumaj
2020 International Colloquium on Automata, Languages and Programming  
We consider two natural subclasses of deterministic top-down tree-to-tree transducers, namely, linear and uniform-copying transducers.  ...  For both classes we show that it is decidable whether the translation of a transducer with look-ahead can be realized by a transducer without look-ahead.  ...  Let How to Remove Look-ahead In the following, we assume that we are given a deterministic top-down tree transducer A with regular look-ahead. By Theorem 7, we may assume that A is earliest.  ... 
doi:10.4230/lipics.icalp.2020.134 dblp:conf/icalp/ManethS20 fatcat:bpiqifi3wzf4bfnv6zxjod54iu

Determinacy and Rewriting of Top-Down and MSO Tree Transformations [chapter]

Michael Benedikt, Joost Engelfriet, Sebastian Maneth
2013 Lecture Notes in Computer Science  
For a large class of non-copying views, namely compositions of functional extended linear top-down tree transducers with regular look-ahead, we show that determinacy is decidable, where queries are given  ...  by deterministic top-down tree transducers with regular lookahead or by MSO tree transducers.  ...  Extended Top-Down and Bottom-Up Tree Transducers An extended top-down tree transducer with regular look-ahead (ET R transducer) is a tuple M = (Q, Σ, Δ, I, R, A) where Q is a ranked alphabet of states  ... 
doi:10.1007/978-3-642-40313-2_15 fatcat:argb3c3fjvcrjc6kfaiqyrazye

Composition Closure of Linear Extended Top-down Tree Transducers [article]

Zoltán Fülöp, Andreas Maletti
2013 arXiv   pre-print
The expressive power of compositions of such transducers with and without regular look-ahead is investigated.  ...  The composition hierarchy turns out to be finite for all epsilon-free (all rules consume input) variants of these transducers except for nondeleting epsilon-free linear extended top-down tree transducers  ...  Secondly, we relate the class l-XT R to l-T R , which tells us how to emulate linear extended top-down tree transducers with regular look-ahead by linear top-down tree transducers with regular look-ahead  ... 
arXiv:1301.1514v1 fatcat:kk27ejgldvg57p7wdndrdcla74

Composition Closure of ε-Free Linear Extended Top-Down Tree Transducers [chapter]

Zoltán Fülöp, Andreas Maletti
2013 Lecture Notes in Computer Science  
The expressive power of compositions of linear extended topdown tree transducers with and without regular look-ahead is investigated.  ...  The composition hierarchy is finite for all ε-free variants of these transducers except for ε-free nondeleting linear extended top-down tree transducers.  ...  Acknowledgment The authors are indebted to an anonymous referee for his valuable report.  ... 
doi:10.1007/978-3-642-38771-5_22 fatcat:khhlbntb4re3tocqsbdiw6kpsa

Deciding equivalence of top–down XML transformations in polynomial time

Joost Engelfriet, Sebastian Maneth, Helmut Seidl
2009 Journal of computer and system sciences (Print)  
Many useful XML transformations can be expressed by deterministic top-down tree transducers. A normal form is presented for such transducers (extended with the facility to inspect their input trees).  ...  Thus, equivalence of transducers in normal form can be decided in polynomial time. If the transducer is total, the normal form can be obtained in polynomial time as well.  ...  A useful extension of the top-down tree transducer is the top-down tree transducer with regular look-ahead [4] .  ... 
doi:10.1016/j.jcss.2009.01.001 fatcat:5uliugceine6ngzltcoe2lufny

The Equivalence of Bottom-Up and Top-Down Tree-to-Graph Transducers

Joost Engelfriet, Heiko Vogler
1998 Journal of computer and system sciences (Print)  
This is in contrast with the well-known incomparability of the usual bottom-up and top-down tree transducers.  ...  We prove that bottom-up tree-to-graph transducers de ne the same tree-to-tree translations as the previously introduced top-down tree-to-graph transducers.  ...  Acknowledgments We would like to thank Christian Lescher for taking over the tedious task of drawing the gures.  ... 
doi:10.1006/jcss.1998.1573 fatcat:u47kv4q2ozhxvmdtpmvz4wtaya

Definability Results for Top-Down Tree Transducers [article]

Sebastian Maneth, Helmut Seidl, Martin Vu
2021 arXiv   pre-print
We prove that for a given deterministic top-down transducer with look-ahead it is decidable whether or not its translation is definable (1)~by a linear top-down tree transducer or (2)~by a tree homomorphism  ...  We present algorithms that construct equivalent such transducers if they exist.  ...  Even more recently, it has been proven that look-ahead removal for linear deterministic top-down tree transducers is decidable [10] .  ... 
arXiv:2105.14860v1 fatcat:47eg2yn5drc5pmxugmowdwtngy

Context-Free Grammars with Storage [article]

Joost Engelfriet
2014 arXiv   pre-print
Taking particular storage types gives particular formalisms, such as indexed grammars, top-down tree transducers, attribute grammars, etc.  ...  To each occurrence of a nonterminal of a context-free S grammar an object of type S is associated, that can be acted upon by tests and operations, as indicated in the rules of the grammar.  ...  Note how funny the development of the notion of look-ahead is: pushdown automata with look-ahead on the input string (in pars- ing theory), top-down tree transducers with look-ahead on the input tree,  ... 
arXiv:1408.0683v1 fatcat:sr2by746tvfenjsotqqop67v2a

Fast

Loris D'antoni, Margus Veanes, Benjamin Livshits, David Molnar
2015 ACM Transactions on Programming Languages and Systems  
To overcome this problem we augment tree automata and transducers with symbolic alphabets represented as parametric theories.  ...  Tree automata and transducers are used in a wide range of applications in software engineering. While these formalisms are of immense practical use, they can only model finite alphabets.  ...  We thank the anonymous reviewers for their valuable feedback that helped us improving the quality of our paper.  ... 
doi:10.1145/2791292 fatcat:mu543ptjgbbzrgygwois3rsx4y

Linear Bounded Composition of Tree-Walking Tree Transducers: Linear Size Increase and Complexity [article]

Joost Engelfriet, Kazuhiro Inaba, Sebastian Maneth
2019 arXiv   pre-print
Compositions of tree-walking tree transducers form a hierarchy with respect to the number of transducers in the composition.  ...  The membership problem for the composition of a nondeterministic and a deterministic tree-walking tree translation (for a nondeterministic IO macro tree translation) is log-space reducible to a context-free  ...  We are grateful to the reviewers for their constructive comments.  ... 
arXiv:1904.09203v3 fatcat:wmhkob2curhnba6hefynpsx6da

Composition Closure of Linear Extended Top-down Tree Transducers

Joost Engelfriet, Zoltán Fülöp, Andreas Maletti
2015 Theory of Computing Systems  
Maletti: Composition closure of ε-free linear extended top-down tree transducers.  ...  The expressive power of compositions of such transducers with and without regular look-ahead is investigated.  ...  It is a linear extended top-down tree transducer (without look-ahead) [l-xt], if c(q) = T Σ for every q ∈ Q la , -a linear top-down tree transducer with regular look ahead [l-t R ] if ∈ Σ(Q) for every  ... 
doi:10.1007/s00224-015-9660-2 fatcat:2y6qisudizgy3d4wfluatwwrui
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