SMOLKA G. and TREINEN R., editors. DFKI Oz Documentation Series, German ResearchCenter for Artificial Intelligence (DFKI), Saarbrucken, Germany,1995.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....programming languages. Concurrency enables us to integrate multiple programming paradigms such as functional [Mil92, Smo94, Nie94, Iba95, PT95b] object oriented [Vas94, PT95a, HSW95, Wal95] and constraint programming [JH91, SSW94] All these paradigms are supported by the programming language Oz [Smo95a, Smo95b]. In this paper, we model the time complexity of eager and lazy functional computation in a concurrent calculus. The importance of complexity is three fold: 1. Every implementation oriented model has to reflect complexity. In the case of lazy functional programming, the consideration of ....

Gert Smolka. An Oz primer. DFKI Oz documentation series, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbr ucken, Germany, 1995.

....an interesting potential. Precisely, feature trees model record structures. They form the semantics of record calculi like [AK86] which are used in symbolic programming languages [AKP91b] and in computational linguistics (cf. the book [Car92] In the logical framework for record structures of [BS92], they constitute the interpretation of a completely axiomatizable, and hence decidable, first order theory. partially supported by Graduierten Kolleg Informatik der Universitat des Saarlandes. As graphs, feature trees are easily described as finite trees whose nodes are labeled by constructor ....

....by different ones. Thus, symbolic keywords called features denote the possible argument positions of a node. They access uniquely the node s direct subtrees. All constructor symbols can label a node with any features attached to it, in any, though finite, number. Although thoroughly investigated [AK86, Smo92, BS92, AKPS92], also in comparison with first order trees [ST92] feature trees have never been characterized as composable elements in an algebraic structure, i.e. with operations defined on them. Also, up to now, there has been no corresponding notion of automata. This device has generally proven useful for ....

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Rolf Backofen and Gert Smolka. A complete and recursive feature theory. Research Report RR-92-30, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, September 1992.

....we call a feature tree. Such a tree is one whose nodes are labeled with sorts and whose edges are labeled with features. Therefore, we can also identify terms that represent the same rational tree. The domain hereby obtained is essentially the feature tree structure T introduced first in [7] and [8]. Unification of terms We say that 1 is unifiable with 2 if 1 2 6= i.e. if there exist terms with non empty denotations that are more specific than both 1 and 2 . Then, one can show that there exists a unique (up to variable renaming) term that is the most general of all these, ....

....OSF unification We describe next how to determine whether an OSF constraint OE is consistent; i.e. if it is satisfiable in some OSF algebra A and, therefore, in particular in Psi . Unification of two terms reduces to this problem. 10 T is essentially the feature tree structure of [7] and [8, 25]. The difference lies in our using partially ordered sorts and total, as opposed to partial, features. June 1991 (Revised, November 1992) Digital PRL Functions as Passive Constraints in LIFE 21 Definition 4 (Solved OSF Constraints) An OSF constraint OE is called solved if for every variable X, ....

Rolf Backofen and Gert Smolka. A complete and decidable feature theory. DFKI Research Report RR-30-92, German Research Center for Artificial Intelligence, Saarbrucken, Germany (1992).

....is available for many platforms running Unix X, including Sparcs and 486 PCs. More information can be retrieved from ftp: ps ftp.dfki.uni sb.de http: ps www.dfki.uni sb.de oz Email addresses: group Gamma oz dfki.uni sb.de Gerd Smolka Gamma smolka dfki.uni sb.de References: 103] 195] [196] [197] 2.76 Panda Developer: University of Kaiserslautern, Germany Description: oo. Panda is a run time package based on a very small operating system kernel which supports distributed applications written in C . memory model. All nodes of a Panda system share a single virtual address space, ....

Gert Smolka. An Oz primer. Technical report, DFKI, German Research Center for Artificial Intelligence, Saarbrucken, Germany, April 1995.

....Oz is available for many platforms running Unix X, including Sparcs and 486 PCs. More information can be retrieved from ftp: ps ftp.dfki.uni sb.de http: ps www.dfki.uni sb.de oz Email addresses: group Gamma oz dfki.uni sb.de Gerd Smolka Gamma smolka dfki.uni sb.de References: 103] [195] [196] 197] 2.76 Panda Developer: University of Kaiserslautern, Germany Description: oo. Panda is a run time package based on a very small operating system kernel which supports distributed applications written in C . memory model. All nodes of a Panda system share a single virtual address ....

Gert Smolka. The definition of kernal Oz. Technical report, DFKI, German Research Center for Artificial Intelligence, Saarbrucken, Germany, 1994.

....Orca [24, 25, 27, 26, 112, 218] Phi Phi Delta Delta H H A A Phi Phi Delta Delta H H A A hijklm y t i v i t c a y r a d n u o b ftp: ftp.cs.vu.nl pub amoeba orca papers ftp: ftp.cs.vu.nl pub papers orca Henri E. Bal Gamma bal cs.vu. nl Oz, Perdio [113, 211, 212, 213] Phi Phi Delta Delta H H A A Phi Phi Delta Delta H H A A hijklm y t i v i t c a y r a d n u o b ftp: ps ftp.dfki.uni sb.de http: ps www.dfki.uni sb.de oz group Gamma oz dfki.uni sb.de Gerd Smolka Gamma smolka dfki.uni sb.de Panda [19] Phi Phi Delta ....

Gert Smolka. An Oz primer. Technical report, DFKI, German Research Center for Artificial Intelligence, Saarbrucken, Germany, April 1995.

....Orca [24, 25, 27, 26, 112, 218] Phi Phi Delta Delta H H A A Phi Phi Delta Delta H H A A hijklm y t i v i t c a y r a d n u o b ftp: ftp.cs.vu.nl pub amoeba orca papers ftp: ftp.cs.vu.nl pub papers orca Henri E. Bal Gamma bal cs.vu. nl Oz, Perdio [113, 211, 212, 213] Phi Phi Delta Delta H H A A Phi Phi Delta Delta H H A A hijklm y t i v i t c a y r a d n u o b ftp: ps ftp.dfki.uni sb.de http: ps www.dfki.uni sb.de oz group Gamma oz dfki.uni sb.de Gerd Smolka Gamma smolka dfki.uni sb.de Panda [19] Phi Phi Delta ....

Gert Smolka. The definition of kernal Oz. Technical report, DFKI, German Research Center for 61 Artificial Intelligence, Saarbrucken, Germany, 1994.

....complex programs. To handle this complexity it is desirable to use a high level language but languages such Lisp, Prolog and Smalltalk does not support concurrency, reactivity and real time control which are vital to VRapplications. However the new concurrent constraint programming language Oz [Smo95] supports all that and is designed for applications that require complex symbolic computations, organization into multiple agents, makes it extremely well suited for VR applications. We have therefore implemented a basic interface between Oz and DIVE. Above this have we implemented an agent ....

Gert Smolka. The definition of kernel oz. Technical report, German Research Center for Artificial Intelligence (DFKI), 1995.

....It provides very elegant solutions to process coordination, and brings the expressiveness of logic rules. But the code gets hard to maintain when the application to implement grows. In fact it lacks some syntactic facilities to enhance source readability. We are now looking more and more at Oz [19]; this language offers together many different paradigms, namely: ffl strong mathematical underlying model, ffl object oriented facilities, ffl constraint based control, ffl logic rules with guards, ffl concurrent execution, ffl open language, ffl embedded graphical user interface tools. All ....

G. Smolka. An Oz primer. Technical report, German Research Center for Artificial Intelligence (DFKI), January 1995. Draft version.

.... two main approaches currently used in concurrent logic programming, and which are seen traditionally as unrelated: shared variable systems, in which communication among parallel tasks is done through logical variables (e.g. Concurrent Prolog [25] PARLOG [12] GHC [30] Janus [24] AKL [20] Oz [27], etc. and distributed or blackboard systems, in which communication is done through explicit built ins which access shared channels or global data areas (e.g. Multi Prolog [2] Shared Prolog [3] and Prologs incorporating Linda [7] being one of the most popular Linda implementations the ....

G. Smolka. The Definition of Kernel Oz. DFKI Oz documentation series, German Research Center for Artificial Intelligence (DFKI), November 1994.

....not require any other primitives than those provided by Oz. It is planned to include the Oz Solver in the next release of the DFKI Oz system. Keywords Constraint Programming, Programming Environment, Debugging, Encapsulated Search, Graphical User Interfaces. 1. Introduction Oz [13] 4] 10] [14] is a concurrent constraint language developed at DFKI supporting higher order functional programming, concurrent object oriented programming, and constraint programming. This paper presents the Oz Solver, a tool designed to support the development of constraint programs. The development of ....

Gert Smolka and Ralf Treinen, editors. DFKI Oz Documentation Series. German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbrucken, Germany, 1995.

....TCP IP. A few systems support higher level functionality layers on top of this interface including linda style blackboards (e.g. SICStus Prolog [7] and Prolog CIAO 1 [16, 17, 14] BinProlog 2 Prolog [26, 2] etc. or shared variable based communication (e.g. KL1 [8] AKL [20] Oz [24], Prolog CIAO [15, 4] etc. In some cases, this functionality is provided via libraries, building on top of the basic TCP IP primitives. This is the case, for example, of the SICStus (and CIAO) linda interface. In fact, as we have shown, shared variable based communication can also be ....

G. Smolka. The Definition of Kernel Oz. DFKI Oz documentation series, German Research Center for Artificial Intelligence (DFKI), November 1994.

....implementation becomes possible. How to read the Definition This report gives a complete and concise definition of Kernel Oz. Supplementary literature is needed to understand the language design and programming in Oz. The reader is expected to have an intuitive understanding of Oz, as conveyed by [14]. More thorough introductions to programming in Oz are [5, 9] The document [4] defines Oz by reduction to Kernel Oz. On first reading, we recommend to ignore the constraint programming aspects of Oz (disjunctions, solvers, finite domains) The study of the Oz calculus should be prepared by ....

Gert Smolka. An Oz primer. DFKI Oz documentation series, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbr ucken, Germany, 1994.

....system, and again apply the memorization technique. Entailment tests for feature constraints, which refine equational constraints for infinite trees, have been treated in [ST92a, AKPS92] In most of those contexts rational and infinite trees can not be distinguished by means of logical formulae [BS92, Mah88]. Membership constraints over sets of finite trees have been considered in [CD91, Uri92] The case of finite feature trees is discussed in [NP93] In these works (generalized) tree automata or regular equation systems with least fixpoint solutions are used. The proposed simplification algorithms ....

....systems by weakening the restriction that they be deterministic. The relaxation of the determinism condition will cause problems in the entailment check. Finally, it will be interesting to apply the methods developed here to the other formalism modeling cyclic data structures: feature trees [ST92a, BS92, AKPS92]. Acknowledgments We are grateful to Gert Smolka. He inspired this work and contributed ideas during the whole development. We would like to thank Hassan Ait Kaci and Hubert Comon for stimulating questions and fruitful discussions. 25 ....

Rolf Backofen and Gert Smolka. A complete and recursive feature theory. Research Report RR-92-30, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, September 1992.

....We see four directions for further research. First, FT should be strengthened such that it subsumes the expressivity of rational constructor trees [7, 8] As is, FT cannot express that x is a tree having direct subtrees at exactly the features f 1 ; f n . It turns out that the system CFT [24] obtained from FT by adding the primitive constraint xff 1 ; f n g (x has direct subtrees at exactly the features f 1 ; f n ) has the same nice properties as FT. In contrast to FT, CFT can express constructor constraints; for instance, the constructor constraint x : A(y; z) ....

G. Smolka and R. Treinen. Relative simplification for and independence of CFT. Draft, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, 1992. To appear. 23

....with the sort A, and letting f(x; y) hold iff x has y as direct subtree via the feature f . The feature tree structure T fixes an algebraic semantics for FT. We will also establish a logical semantics, which is given by three axiom schemes fixing a first order theory FT. Backofen and Smolka [6] show that T is a model of FT and that FT is in fact a complete theory, which means that FT is exactly the theory induced by T . However, we will not use the completeness result in the present paper, but show explicitly that entailment with respect to T is the same as entailment with respect to ....

....Mukai [17, 18] These early feature structure formalism were presented in a nonlogical form. Major steps in the process of their understanding and logical reformulation are the articles [20, 23, 11, 22] Feature trees, the feature tree structure T , and the axiomatization of T were first given in [6]. The paper is organized as follows. Section 2 defines the basic notions and discusses the differences in expressivity between Herbrand and FT. Section 3 gives a basic simplification system that decides satisfiability of positive constraints. Section 4 is not committed to FT but discusses the ....

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R. Backofen and G. Smolka. A complete and decidable feature theory. Draft, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, 1991. To appear.

....Due to space limitations the paper does not contain the proofs of the claimed results. We also cannot give an algorithmic formulation of our decision method, which would exhibit its incrementality and worst case complexity. Both proofs and algorithmic formulation are given in the full paper [21]. 2 The Feature Tree Structure This section gives a formal definition of CFT s standard model T . T is a first order structure whose universe consists of all feature trees obtainable from given alphabets of sorts and features. From now on we assume that an infinite alphabet SOR of symbols called ....

G. Smolka and R. Treinen. Records for logic programming. Research Report RR-9223, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, 1992.

....point circle 2 7 center radius type nat or 0 1 s def 1 2 2 3 point xval yval xval 2 red point name 3 color Figure 1: Examples of Feature Trees. finite trees as in the original Horn clause model is also possible. 1. 1 Records are Feature Trees We model records as feature trees [6, 7]. A feature tree (examples are shown in Figure 1) is a tree whose edges are labeled with symbols called features, and whose nodes are labeled with symbols called sorts. The features labeling the edges correspond to the field names of records. As one would expect, the labeling with features must be ....

....is Ait Kaci s term calculus [1, 2] which is the basis of several constraint programming languages [3, 4, 5] Smolka [20] gives a unified logical view of most earlier feature formalisms and studies an expressive feature constraint logic. Feature trees appeared only recently with the work on FT [7, 6]. To our knowledge the notion of an arity constraint is new. Carpenter s [8] extensional types are somewhat related in that they fix an arity for all elements of a type. 1.5 Organization of the Paper Section 2 gives a formal definition of the feature tree structure, thus fixing syntax and ....

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R. Backofen and G. Smolka. A complete and recursive feature theory. Research Report RR-92-30, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 6600 Saarbrucken 11, Germany, July 1992.

....of AGENTS versus clp(FD) 10.2 Evaluating AGENTS with Copying In this section we are using the copying scheme for labeling developed in Section 9.5.1. 10.2. 1 Comparing with Oz We now compare AGENTS with Oz, which offers the same basic functionality for finite domain constraints as do AGENTS [Smo95, HM95, MMPS95, MPSW95]. The machine used throughout in the evaluation is a Sun 4 25 (SPARCstation ELC) running SunOs 4.1.2, and all measurements are done on this machine. In Table 10.9 we give the timings in milliseconds for the same programs run in AGENTS and in Oz. This time, we use the copying based backtracking ....

....and cumulative constraints; however, the basic foundation has been laid upon which such constructs should fit nicely. 11.2 Constraint Programming Systems 143 11.2. 6 Oz Oz is a concurrent language allowing functional, object oriented and constraint programming, based on the CCP paradigm [Smo95, HM95, MMPS95, MPSW95]. Similar to AKL, Oz provides deep guards, and the same three guard operators for conditional, committed and nondeterminate choice are included. The language is higher order which enables a theoretically appealing treatment of objects and inheritance [Smo94] Oz includes a combinator for ....

G. Smolka. An Oz Primer. Oz Documentation Series, DFKI, German Research Center for Artificial Intelligence, 1995.

....programming applications (with the recent exception of [Mei95] 1 This paper describes a visual constraint programming tool, called Oz Explorer, for Oz. Oz is a concurrent constraint language providing for functional, object oriented, and constraint programming [Smo95b, HSW95, SSW94, SS94, ST95] It has a simple yet powerful computation model [Smo95b, Smo95a] which extends the concurrent constraint model [Mah87, SR90] by first class procedures, concurrent state and encapsulated search. The Explorer uses the search tree as its central metaphor. The user can interactively explore the ....

Gert Smolka and Ralf Treinen, editors. DFKI Oz Documentation Series. German Research Center for Artificial Intelligence (DFKI), Saarbrucken, Germany, 1995.

....Oz programming model, these styles smoothly integrate to yield, e.g. a first order logic language, a higher order constraint language, a concurrent object oriented language, or a functional language. Since explanation of the examples has to be brief, we refer the reader to the Oz documentation [ST95]. The sample applications in the DFKI Oz release illustrate how paradigms mix in larger programs. For instance, a multi agent transportation scenario is set up as a collection of concurrent objects which interact with each other while locally performing speculative computation. The Oz programming ....

Gert Smolka and Ralf Treinen, editors. DFKI Oz Documentation Series. German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbrucken, Germany, 1995.

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SMOLKA G. and TREINEN R., editors. DFKI Oz Documentation Series, German ResearchCenter for Artificial Intelligence (DFKI), Saarbrucken, Germany,1995.

No context found.

SMOLKA G. and TREINEN R., editors. DFKI Oz Documentation Series, German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbrucken, Germany, 1995.

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G. Smolka, R. Treinen, et al. DFKI Oz documentation series. German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, 66123 Saarbrucken, Germany, 1995.

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G. Smolka and R. Treinen (Eds.). DFKI Oz Documentation Series. German Research Center for Artificial Intelligence (DFKI), Stuhlsatzenhausweg 3, D-66123 Saarbrucken, Germany, 1996.

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