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12
Deterministic Consistency Checking of LP Constraints
, 1995
"... We provide a constraint based computational model of linear precedence as employed in the HPSG grammar formalism. An extended feature logic which adds a wide range of constraints involving precedence is described. A sound, complete and terminating deterministic constraint solving procedure is given. ..."
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Cited by 16 (4 self)
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We provide a constraint based computational model of linear precedence as employed in the HPSG grammar formalism. An extended feature logic which adds a wide range of constraints involving precedence is described. A sound, complete and terminating deterministic constraint solving procedure is given. Deterministic computational model is achieved by weakening the logic such that it is sufficient for linguistic applications involving wordorder.
Situated Simplification
 THEORETICAL COMPUTER SCIENCE
, 1997
"... Testing satisfaction of guards is the essential operation of concurrent constraint programming (CCP) systems. We present and prove correct, for the first time, an incremental algorithm for the simultaneous tests of entailment and disentailment of rational tree constraints to be used in CCP syste ..."
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Cited by 7 (1 self)
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Testing satisfaction of guards is the essential operation of concurrent constraint programming (CCP) systems. We present and prove correct, for the first time, an incremental algorithm for the simultaneous tests of entailment and disentailment of rational tree constraints to be used in CCP systems with deep guards (e.g., in AKL or in Oz). The algorithm is presented as the simplification of the constraints which form the (possibly deep) guards and which are situated at different nodes in a tree (of arbitrary depth). The nodes correspond to local computation spaces. In this algorithm, a variable may have multiple bindings (which each represent a constraint on that same variable in a different node). These may be realized in various ways. We give a simple fixedpoint algorithm and use it for proving that the tests implemented by another, practical algorithm are correct and complete for entailment and disentailment. We formulate the results in this paper for rational tree constraints; they can be adapted to finite and feature trees.
Extending Unification Formalisms
 In Proceedings of the 2nd Language Engineering Convention. London and
, 1995
"... This paper describes some of the results of the project The Reusability of Grammatical Resources. The aim of the project is to extend current grammar formalisms with notational devices and constraint solvers in order to aid the development of reusable grammars. The project took the Advanced Linguist ..."
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Cited by 7 (2 self)
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This paper describes some of the results of the project The Reusability of Grammatical Resources. The aim of the project is to extend current grammar formalisms with notational devices and constraint solvers in order to aid the development of reusable grammars. The project took the Advanced Linguistic Engineering Platform (ALEP) as its starting point. ALEP allows two levels of extension: additional syntactic expressions (“syntactic sugar”) and specialised external constraint solvers. Our syntactic additions to ALEP comprise support for LFG coherence and completeness and an extended notation for phrasestructure rules. The project has developed solvers for set constraints, set operations, linear precedence constraints and guarded constraints. The extensions were formally specified and implemented as Prolog modules and hence have a wider applicability. These can be either used standalone or integrated within existing grammar formalisms. We have sucessfully integrated the all constraint solvers with the ProFIT typed feature system and these have been partially integrated into ALEP. 1
Entailment and Disentailment of OrderSorted Feature Constraints
 In Proceedings of the Fourth International Conferenceon Logic Programmingand Automated Reasoning, Andrei Voronkov
, 1993
"... LIFE uses matching on ordersorted feature structures for passing arguments to functions. As opposed to unication which amounts to normalizing a conjunction of constraints, solving a matching problem consists of deciding whether a constraint (guard) or its negation are entailed by the context. We gi ..."
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Cited by 6 (3 self)
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LIFE uses matching on ordersorted feature structures for passing arguments to functions. As opposed to unication which amounts to normalizing a conjunction of constraints, solving a matching problem consists of deciding whether a constraint (guard) or its negation are entailed by the context. We give a complete and consistent set of rules for entailment and disentailment of ordersorted feature constraints. These rules are directly usable for relative simplification, a general prooftheoretic method for proving guards in concurrent constraint logic languages using guarded rules.
SetBased Failure Analysis for Logic Programs and Concurrent Constraint Programs
 PROGRAMMING LANGUAGES AND SYSTEMS, 8TH EUROPEAN SYMPOSIUM ON PROGRAMMING, ESOP'99, VOLUME 1576 OF LNCS
, 1999
"... This paper presents the first approximation method of the finitefailure set of a logic program by setbased analysis. In a dual view, the method yields a type analysis for programs with ongoing behaviors (perpetual processes). Our technical contributions are (1) the semantical characterization ..."
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Cited by 6 (1 self)
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This paper presents the first approximation method of the finitefailure set of a logic program by setbased analysis. In a dual view, the method yields a type analysis for programs with ongoing behaviors (perpetual processes). Our technical contributions are (1) the semantical characterization of finite failure of logic programs over infinite trees and (2) the design and soundness proof of the first setbased analysis of logic programs with the greatestmodel semantics. Finally, we exhibit the connection between finite failure and the inevitability of the `inconsistentstore ' error in fair executions of concurrent constraint programs where no process suspends forever. This indicates a potential application to error diagnosis for concurrent constraint programs.
On ConstraintBased Lambek Calculi
"... We explore the consequences of layering a Lambek proof system over an arbitrary (constraint) logic. A simple modeltheoretic semantics for our hybrid language is provided for which a particularly simple combination of Lambek's and the proof system of the base logic is complete. Furthermore th ..."
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Cited by 4 (0 self)
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We explore the consequences of layering a Lambek proof system over an arbitrary (constraint) logic. A simple modeltheoretic semantics for our hybrid language is provided for which a particularly simple combination of Lambek's and the proof system of the base logic is complete. Furthermore the proof system for the underlying base logic can be assumed to be a black box. The essential reasoning needed to be performed by the black box is that of entailment checking. Assuming feature logic as the base logic entailment checking amounts to a subsumption test which is a wellknown quasilinear time decidable problem.
DF Constraint System
 In Proceeding of the First International Workshop on Concurrent Constraint Programming, Ph. Codognet
, 1995
"... This work presents DF, a feature constraint system that starting from the main lines of the two major approaches in the field  the OSF system of Hassan AitKaci, and the CFT system of Gert Smolka  provides for new significant characteristics: a firstclass citizen status offered to (both fea ..."
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Cited by 2 (2 self)
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This work presents DF, a feature constraint system that starting from the main lines of the two major approaches in the field  the OSF system of Hassan AitKaci, and the CFT system of Gert Smolka  provides for new significant characteristics: a firstclass citizen status offered to (both features and) sorts, finer grained constraints using arguments in the feature context, welltype conditioning between feature values and types, and principlebased completion of sort signature.
Data models as constraint systems: A key to the semantic web. Research paper, submitted for publication
, 2007
"... This article illustrates how constraint logic programming can be used to express data models in rulebased languages, including those based on graph patternmatching or unification to drive rule application. This is motivated by the interest in using constraintbased technology in conjunction with ru ..."
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Cited by 1 (1 self)
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This article illustrates how constraint logic programming can be used to express data models in rulebased languages, including those based on graph patternmatching or unification to drive rule application. This is motivated by the interest in using constraintbased technology in conjunction with rulebased technology to provide a formally correct and effective—indeed, efficient!—operational base for the semantic web.
DF  a Feature Constraint System and its Extension to a Logic Concurrent Language
"... This paper presents a feature constraint system that, compared with the wellknown systems OSF[1] and CFT[5], incorporates several interesting characteristics. The new system, called DF, is naturally extended through the CLP scheme (in combination with a dynamic completion technique) to a logic ..."
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This paper presents a feature constraint system that, compared with the wellknown systems OSF[1] and CFT[5], incorporates several interesting characteristics. The new system, called DF, is naturally extended through the CLP scheme (in combination with a dynamic completion technique) to a logic language equally called DF.