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31
Microarchitecture Modeling for DesignSpace Exploration DesignSpace Exploration
, 2004
"... To identify the best processor designs, designers explore a vast design space. To assess the quality of candidate designs, designers construct and use simulators. Unfortunately, simulator construction is a bottleneck in this designspace exploration because existing simulator construction methodolog ..."
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Cited by 10 (2 self)
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To identify the best processor designs, designers explore a vast design space. To assess the quality of candidate designs, designers construct and use simulators. Unfortunately, simulator construction is a bottleneck in this designspace exploration because existing simulator construction methodologies lead to long simulator development times. This bottleneck limits exploration to a small set of designs, potentially diminishing quality of the final design.
The Decidability of Simultaneous Rigid EUnification with One Variable
 REWRITING TECHNIQUES AND APPLICATIONS
, 1997
"... We show that simultaneous rigid Eunification, or SREU for short, is decidable and in fact EXPTIMEcomplete in the case of one variable. This result implies that the ... fragment of intuitionistic logic with equality is decidable. Together with a previous result regarding the undecidability of the ..."
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Cited by 10 (10 self)
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We show that simultaneous rigid Eunification, or SREU for short, is decidable and in fact EXPTIMEcomplete in the case of one variable. This result implies that the ... fragment of intuitionistic logic with equality is decidable. Together with a previous result regarding the undecidability of the 99fragment, we obtain a complete classification of decidability of the prenex fragment of intuitionistic logic with equality, in terms of the quantifier prefix. It is also proved that SREU with one variable and a constant bound on the number of rigid equations is Pcomplete.
Efficient inclusion checking for deterministic tree automata and xml schemas
, 2007
"... Abstract. We present a new algorithm for testing language inclusion L(A) ⊆ L(B) between tree automata in time O(A  ∗ B) where B is deterministic. We extend this algorithm for testing inclusion between automata for unranked trees A and deterministic DTDs D in time O(A∗ Σ  ∗ D). No previo ..."
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Cited by 10 (3 self)
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Abstract. We present a new algorithm for testing language inclusion L(A) ⊆ L(B) between tree automata in time O(A  ∗ B) where B is deterministic. We extend this algorithm for testing inclusion between automata for unranked trees A and deterministic DTDs D in time O(A∗ Σ  ∗ D). No previous algorithms with these complexities exist. inria00192329, version 6 5 Mar 2009 1
Unification in extensions of shallow equational theories
 REWRITING TECHNIQUES AND APPLICATIONS, 9TH INTERNATIONAL CONFERENCE, RTA98', VOL. 1379 OF LNCS
, 1998
"... We show that unification in certain extensions of shallow equational theories is decidable. Our extensions generalize the known classes of shallow or standard equational theories. In order to prove decidability of unification in the extensions, a class of Horn clause sets called sorted shallow equa ..."
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Cited by 9 (1 self)
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We show that unification in certain extensions of shallow equational theories is decidable. Our extensions generalize the known classes of shallow or standard equational theories. In order to prove decidability of unification in the extensions, a class of Horn clause sets called sorted shallow equational theories is introduced. This class is a natural extension of tree automata with equality constraints between brother subterms as well as shallow sort theories. We show that saturation under sorted superposition is effective on sorted shallow equational theories. So called semilinear equational theories can be e ectively transformed into equivalent sorted shallow equational theories and generalize the classes of shallow and standard equational theories.
Complexity of decision problems for XML schemas and chain regular expressions
 Siam J. Comp
"... Abstract. We study the complexity of the inclusion, equivalence, and intersection problem of extended CHAin Regular Expressions (eCHAREs). These are regular expressions with a very simple structure: they basically consist of the concatenation of factors, where each factor is a disjunction of strings ..."
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Cited by 9 (6 self)
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Abstract. We study the complexity of the inclusion, equivalence, and intersection problem of extended CHAin Regular Expressions (eCHAREs). These are regular expressions with a very simple structure: they basically consist of the concatenation of factors, where each factor is a disjunction of strings, possibly extended with “∗”, “+”, or “?”. Though of a very simple from, the usage of such expressions is widespread as eCHAREs, for instance, constitute a super class of the regular expressions most frequently used in practice in schema languages for XML. In particular, we show that all our lower and upper bounds for the inclusion and equivalence problem carry over to the corresponding decision problems for extended contextfree grammars, and to singletype and restrained competition tree grammars. These grammars form abstractions of Document Type Definitions (DTDs), XML Schema definitions (XSDs) and the class of onepass preorder typeable XML schemas, respectively. For the intersection problem, we show that obtained complexities only carry over to DTDs. In this respect, we also study two other classes of regular expressions related to XML: deterministic expressions and expressions where the number of occurrences of alphabet symbols is bounded by a constant. 1. Introduction. Although
Rigid Tree Automata
, 2008
"... We introduce the class of Rigid Tree Automata (RTA), an extension of standard bottomup automata on ranked trees with distinguished states called rigid. Rigid states define a restriction on the computation of RTA on trees: two subtrees reaching the same rigid state in a run must be equal. RTA are ab ..."
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Cited by 8 (0 self)
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We introduce the class of Rigid Tree Automata (RTA), an extension of standard bottomup automata on ranked trees with distinguished states called rigid. Rigid states define a restriction on the computation of RTA on trees: two subtrees reaching the same rigid state in a run must be equal. RTA are able to perform local and global tests of equality between subtrees, nonlinear tree pattern matching, and restricted disequality tests as well. Properties like determinism, pumping lemma, Boolean closure, and several decision problems are studied in detail. In particular, the emptiness problem is shown decidable in linear time for RTA whereas membership of a given tree to the language of a given RTA is NPcomplete. Our main result is that is decidable whether a given tree belongs to the rewrite closure of a RTA language under a restricted family of term rewriting systems, whereas this closure is not a RTA language. This result, one of the first on rewrite closure of languages of tree automata with constraints, is enabling the extension of model checking procedures based on finite tree automata techniques. Finally, a comparison of RTA with several classes of tree automata with local and global equality tests, and with dag automata is also provided.
Facilitating reuse in hardware models with enhanced type inference
 In Proceedings of the 2004 Conference on Hardware/Software Codesign and System Synthesis (CODES+ISSS
, 2004
"... Highlevel hardware modeling is an essential, yet timeconsuming, part of system design. However, effective componentbased reuse in hardware modeling languages can reduce model construction time and enable the exploration of more design alternatives, leading to better designs. While component overl ..."
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Cited by 8 (3 self)
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Highlevel hardware modeling is an essential, yet timeconsuming, part of system design. However, effective componentbased reuse in hardware modeling languages can reduce model construction time and enable the exploration of more design alternatives, leading to better designs. While component overloading and parametric polymorphism are critical for effective componentbase reuse, no existing modeling language supports both. The lack of these features creates overhead for designers that discourages reuse, negating any benefits of reuse. This paper presents a type system which supports both component overloading and parametric polymorphism. It proves that performing type inference for any such system is NPcomplete and presents a heuristic that works efficiently in practice. The result is a type system and type inference algorithm that can encourage reuse, reduce design specification time, and lead to better designs. Categories and Subject Descriptors:
Directional Type Checking for Logic Programs: Beyond Discriminative Types
 In Proc. of ESOP 2000
, 2000
"... Directional types form a type system for logic programs which is based on the view of a predicate as a directional procedure which, when applied to a tuple of input terms, generates a tuple of output terms. It is known that directionaltype checking wrt. arbitrary types is undecidable; several autho ..."
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Cited by 7 (1 self)
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Directional types form a type system for logic programs which is based on the view of a predicate as a directional procedure which, when applied to a tuple of input terms, generates a tuple of output terms. It is known that directionaltype checking wrt. arbitrary types is undecidable; several authors proved decidability of the problem wrt. discriminative regular types. In this paper, using techniques based on tree automata, we show that directionaltype checking for logic programs wrt. general regular types is DEXPTIMEcomplete and fixedparameter linear. The letter result shows that despite the exponential lower bound, the type system might be usable in practice.
Complexity of Subtype Satisfiability over Posets
 in "14th European Symposium on Programming", LNCS
, 2005
"... Subtype satisfiability is an important problem for designing advanced subtype systems and subtypebased program analysis algorithms. The problem is well understood if the atomic types form a lattice. However, little is known about subtype satisfiability over posets. In this paper, we investigate alg ..."
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Cited by 5 (0 self)
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Subtype satisfiability is an important problem for designing advanced subtype systems and subtypebased program analysis algorithms. The problem is well understood if the atomic types form a lattice. However, little is known about subtype satisfiability over posets. In this paper, we investigate algorithms for and the complexity of subtype satisfiability over general posets. We present a uniform treatment of different flavors of subtyping: simple versus recursive types and structural versus nonstructural subtype orders. Our results are established through a new connection of subtype constraints and modal logic. As a consequence, we settle a problem left open by Tiuryn and Wand in 1993. 1