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18
A comparison of pebble tree transducers with macro tree transducers
 Acta Informatica
, 2003
"... Abstract. The npebble tree transducer was recently proposed as a model for XML query languages. The four main results on deterministic transducers are: First, (1) the translation τ of an npebble tree transducer can be realized by a composition of n + 1 0pebble tree transducers. Next, the pebble t ..."
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Abstract. The npebble tree transducer was recently proposed as a model for XML query languages. The four main results on deterministic transducers are: First, (1) the translation τ of an npebble tree transducer can be realized by a composition of n + 1 0pebble tree transducers. Next, the pebble tree transducer is compared with the macro tree transducer, a wellknown model for syntaxdirected semantics, with decidable type checking. The 0pebble tree transducer can be simulated by the macro tree transducer, which, by the first result, implies that (2) τ can be realized by an (n+1)fold composition of macro tree transducers. Conversely, every macro tree transducer can be simulated by a composition of 0pebble tree transducers. Together these simulations prove that (3) the composition closure of npebble tree transducers equals that of macro tree transducers (and that of 0pebble tree transducers). Similar results hold in the nondeterministic case. Finally, (4) the output languages of deterministic npebble tree transducers form a hierarchy with respect to the number n of pebbles. 1
Structured document transformations based on XSL
 In DBPL
, 1999
"... Abstract. Based on the recursion mechanism of the XML transformation language XSL, the document transformation language DTL is defined. First the instantiation DTL reg is considered that uses regular expressions as pattern language. This instantiation closely resembles the navigation mechanism of XS ..."
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Cited by 39 (13 self)
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Abstract. Based on the recursion mechanism of the XML transformation language XSL, the document transformation language DTL is defined. First the instantiation DTL reg is considered that uses regular expressions as pattern language. This instantiation closely resembles the navigation mechanism of XSL. For DTL reg the complexity of relevant decision problems such as termination of programs, usefulness of rules and equivalence of selection patterns, is addressed. Next, a much more powerful abstraction of XSL is considered that uses monadic secondorder logic formulas as pattern language (DTL mso). If DTL mso is restricted to topdown transformations (DTL mso d), then a computational model can be defined which is a natural generalization to unranked trees of topdown tree transducers with lookahead. The lookahead can be realized by a straightforward bottomup preprocessing pass through the document. The size of the output of an XSL program is at most exponential in the size of the input. By restricting copying in XSL a decidable fragment of DTL mso d programs is obtained which induces transformations of linear size increase (safe DTL mso d). It is shown that the emptiness and finiteness problems are decidable for ranges of DTL mso d programs and that the ranges are closed under intersection with generalized Document Type Definitions (DTDs). 1
Macro Tree Translations of Linear Size Increase are MSO Definable
 SIAM J. Comput
, 2001
"... Abstract. The first main result is that if a macro tree translation is of linear size increase, i.e., if the size of every output tree is linearly bounded by the size of the corresponding input tree, then the translation is MSO definable (i.e., definable in monadic secondorder logic). This gives a ..."
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Cited by 23 (8 self)
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Abstract. The first main result is that if a macro tree translation is of linear size increase, i.e., if the size of every output tree is linearly bounded by the size of the corresponding input tree, then the translation is MSO definable (i.e., definable in monadic secondorder logic). This gives a new characterization of the MSO definable tree translations in terms of macro tree transducers: they are exactly the macro tree translations of linear size increase. The second main result is that given a macro tree transducer, it can be decided whether or not its translation is MSO definable, and if it is then an equivalent MSO transducer can be constructed. Similar results hold for attribute grammars, which define a subclass of the macro tree translations.
TreeBased Picture Generation
 Theoretical Computer Science
, 2000
"... . The concept of treebased picture generation is introduced. It is shown that there are equivalent treebased definitions of four picturegenerating devices known from the literature, namely collage grammars, mutually recursive function systems, contextfree chaincode grammars, and 0Lsystems with ..."
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Cited by 14 (8 self)
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. The concept of treebased picture generation is introduced. It is shown that there are equivalent treebased definitions of four picturegenerating devices known from the literature, namely collage grammars, mutually recursive function systems, contextfree chaincode grammars, and 0Lsystems with turtle interpretation. Furthermore, generalisations of each of these systems are discussed. 1 Introduction During the last two decades picture generation has become a large field whose manyfold aspects are studied in mathematics as well as in practical and theoretical computer science. It attracts the interest of numerous researchers from diverse directions, which is no surprise because one can find in this area a great number of intellectually appealing mathematical and computational problems, interesting applications like the modelling of plant development and, one should not forget to mention this, an astonishing variety of beautiful pictures. In this paper picture generation is studied...
TREEBAG  A TreeBased Generator for Objects of Various Types
 Bericht Nr. 1/98, Universitat Bremen, Fachbereich Mathematik und Informatik
, 1998
"... . A software system called TreebagTreeBased Generatoris presented. The aim behind Treebag is to allow for the generation and visualization of objects of all kinds: pictures, trees, graphs, strings, numbers, etc. The basic principle is that tree generators like, for instance, regular tree gram ..."
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Cited by 9 (4 self)
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. A software system called TreebagTreeBased Generatoris presented. The aim behind Treebag is to allow for the generation and visualization of objects of all kinds: pictures, trees, graphs, strings, numbers, etc. The basic principle is that tree generators like, for instance, regular tree grammars, generate terms over symbols that are interpreted by appropriate algebras as operations on the domain of objects under consideration. Thus, every term is viewed as an expression that denotes one of the objects of interest. These objects can be visualized using appropriate displays. 1 Introduction In mathematics and computer science, one of the most natural and universal ways to denote elements of a given data space is to use expressions over a suitable set of operations, like p 3=7 + 5. The usefulness of this concept is even strengthened by the fact that such an expression may contain variablesin which case it does not denote a particular, single object, but a set of objects or a ...
String Languages Generated by Total Deterministic Macro Tree Transducers
 Proc. FOSSACS'99, volume 1578 of LNCS
"... . The class of string languages obtained by taking the yields of output tree languages of total deterministic macro tree transducers (MTTs) is investigated. The first main result is that MTTs which are linear and nondeleting in the parameters generate the same class of string languages as total dete ..."
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. The class of string languages obtained by taking the yields of output tree languages of total deterministic macro tree transducers (MTTs) is investigated. The first main result is that MTTs which are linear and nondeleting in the parameters generate the same class of string languages as total deterministic topdown tree transducers. The second main result is a so called "bridge theorem"; it can be used to show that there is a string language generated by a nondeterministic topdown tree transducer with monadic input, i.e., an ET0L language, which cannot be generated by an MTT. In fact, it is shown that this language cannot even be generated by the composition closure of MTTs; hence it is also not in the IOhierarchy. 1
The Complexity of Tree Transducer Output Languages
, 2008
"... Two complexity results are shown for the output languages generated by compositions of macro tree transducers. They are in NSPACE(n) and hence are contextsensitive, and the class is NPcomplete. ..."
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Cited by 4 (3 self)
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Two complexity results are shown for the output languages generated by compositions of macro tree transducers. They are in NSPACE(n) and hence are contextsensitive, and the class is NPcomplete.
Maneth; Twoway finite state transducers with nested pebbles
 Proc. MFCS 2002, Lecture Notes in Computer Science 2420
, 2002
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Models of Tree Translation
"... This first chapter gives an introduction into the area of tree transducer theory, and describes the results presented in Chapters 2–6. The first section addresses general issues like translations, trees, and tree grammars. Section 2 is concerned with the different models of tree transducers that ar ..."
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Cited by 4 (1 self)
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This first chapter gives an introduction into the area of tree transducer theory, and describes the results presented in Chapters 2–6. The first section addresses general issues like translations, trees, and tree grammars. Section 2 is concerned with the different models of tree transducers that are considered in the thesis. It describes the typical problems that appear in tree transducer theory, and mentions important properties of the different tree transducer models. Section 3 describes the results of
2013): LookAhead Removal for TopDown Tree Transducers. CoRR abs/1311.2400
"... Abstract. Topdown tree transducers are a convenient formalism for describing tree transformations. They can be equipped with regular lookahead, which allows them to inspect a subtree before processing it. In certain cases, such a lookahead can be avoided and the transformation can be realized by ..."
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Abstract. Topdown tree transducers are a convenient formalism for describing tree transformations. They can be equipped with regular lookahead, which allows them to inspect a subtree before processing it. In certain cases, such a lookahead can be avoided and the transformation can be realized by a transducer without lookahead. Removing the lookahead from a transducer, if possible, is technically highly challenging. For a restricted class of transducers with lookahead, namely those that are total, deterministic, ultralinear, and bounded erasing, we present an algorithm that, for a given transducer from that class, (1) decides whether it is equivalent to a total deterministic transducer without lookahead, and (2) constructs such a transducer if the answer is positive. For the whole class of total deterministic transducers with lookahead we present a similar algorithm, which assumes that a socalled difference bound is known for the given transducer. The designer of a transducer can usually also determine a difference bound for it. 1