M. Bugliesi. A declarative view of inheritance in logic programming. In Krzysztof Apt, editor, Proceedings of the Joint International Conference and Symposium on Logic Programming, pages 113-- 127, Washington, USA, 1992. The MIT Press.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....inheritance. We are then required to deal with inheritance con icts and as a consequence may have to settle for multiple minimal models at the declarative level, e.g. as in [16] Current solutions that are proposed in the literature are based on non monotonic reasoning [26] program composition [5], etc. These proposals have been criticized due to the skepticism about their feasibility as an ecient computational platform. Behavioral inheritance has been studied in deductive formalisms like the Ordered Theories of [17] in modular languages such as Contextual Logic Programming [23, 24] and ....

....6.2 2 7 Related Research There are several important di erences between our language and others . Behavioral inheritance has been studied in the context of Ordered Theories [17] Contextual Logic Programming [23, 24] arti cial intelligence, non monotonic reasoning, and a few others such as [5, 6]. Research in arti cial intelligence and non monotonic reasoning is mainly concerned with inheritance of properties and con icts, and do not consider behaviors and structures of objects in object oriented databases. Some of the proposals also sacri ce completeness, or are highly ....

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M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113-130. The MIT Press, 1992.

.... the moin purpose of o concurrent tronsoction model is to keep integrity of doto [58] Along this woy we find Contextuol Logic Progromming [51, 52] ond messoges used os o woy to ochieve o logicol reinterpretorion for some of the distinguishing feotures of the object oriented progromming porodigm [49, 27]. A prototypicol system supporting knowledge portitioned in theories ond in which gool refutotion con move from one theory to onother through context switches, which ore messoge colls, is KBMS1 [48] Since in this opprooch the longuoges considered ore extensions of Horn clouse longuoges, their By ....

....proposal adopts a lexical (static) policy of scope. Further extensions capturing a notion of dynamic scoping while retaining the overriding semantics have been proposed. Message passing and inheritance Message passing and inheritance are embodied in logic programming in the SelfLog language [27], which has been greatly influenced from the Class Template Language proposed by McCabe [49] Ob jectLog is an extended Horn clauses language which has an embedded form of modularity whereby a set of clauses can be collected into a named theory (an object, or unit) and different objects can ....

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M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In K. R. Apt, editor, Proc. Ninth Lnt'l Conf. on Logic Programming, pages 113 127, 1992.

....be targeting Portuguese, obviously) with concepts and vocabulary appropriate for the information contained within SIIUE. Use of Contextual Logic Programming. The case for Contextual Logic Programming [22, 5] CxLP for short) has already been made from several points of view, see for example [4, 10, 16, 18]. It is our belief that using CxLP as a basic feature in ISCO should bring about tangible benefits to the language, from a practical application development point of view. Furthermore, features such as schema evolution may be expressed very naturally in CxLP. Work towards a CxLP implementation for ....

M. Bugliesi. A declarative view of inheritance in logic programming. In Krzysztof Apt, editor, Proceedings of the Joint International Conference and Symposium on Logic Programming, pages 113--127, Washington, USA, 1992. The MIT Press. 8

....of de nite programs can be expressed in Alloy. Finally, as far as the semantics of program compositions is concerned, it is worth recalling that the idea of extending the immediate consequence operator into a mapping over sets of Herbrand interpretations was also used in di erent settings such as [8, 20, 21]. A number of extensions of logic programming to feature modularity have been also proposed. A comprehensive survey on extensions of logic programming for program composition and modularity can be found in [1] Miller [7] proposes a logical system richer than Horn clauses to deal with ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proceedings Joint International Conference and Symposium on Logic Programming, pages 113{ 130. The MIT Press, 1992.

....rules is equivalent to positive relational algebra. Several interesting proposals have been made that introduce object oriented features into the deductive framework [KLW94, ALUW93, KA89] Moreover, inheritance has been treated successfully by introducing principles from modular logic programming [Bug92, BLM94, AKM97] Modularity is a special form of program composition that allows incremental development and code reusability. One of its forms in logic programming is supplied by units [MP89] Units consist of named pieces of code and each unit has its own name space. Encapsulation in the logic ....

....mechanism in object oriented terms. This structure calls for new composition operators as the usual modular programming operators do not apply in our case. The operators were defined along the lines of logic programming composition operators such as the union [MP88] and the overriding union [Bug92] operators. By the union operator, two programs are combined to produce one that consists of the set theoretic union of the clauses of the original programs. Using the overriding union, though, clauses of the second program that define predicates already defined in the first program are not ....

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M. Bugliesi. A declarative view of inheritance in logic programming. In Joint International Conference and Symposium on Logic Programming, pages 112--127, 1992.

....programs with negation (datalog neg ) datalog neg is used as a standard evaluator as well as a semantics provider. In [JL95] the semantics of behavioral inheritance that are given capture the idea of method withdrawal as a solution to the resolution of method definition conflicts. Bugliesi in [Bug92] approaches the issue of behavioral inheritance through a compositional view of extended Horn clause programs. The programs are composed via operators and semantics are given as a function over Herbrand sets rather than as a simple Herbrand set. In this paper, we discuss various kinds of ....

....first introduced in [O K85] have been followed by various researchers [Bro93, BMPT90, MP88] In the second approach, the language of Horn clauses has been extended to allow implication goals in the bodies. The pioneer work is presented in [Mil86] and the work in [MP89] is an eminent one. In [Bug92], an attempt was made to combine the two approaches, proposing SelfLog, a framework where both paradigms co exist. The paper is organized as follows. In Section 2, some information concerning the background of the framework is presented. In Sections 3 and 4, two rather common forms of ....

[Article contains additional citation context not shown here]

M. Bugliesi. A declarative view of inheritance in logic programming. In Joint International Conference and Symposium on Logic Programming, pages 112--127, 1992.

....been proposed in the literature to define structured logic languages more coherent with the logic paradigm. These proposals cover a wide space, ranging from the conventional notion of scope rule and blockbased programming [1] to the integration into the logic framework of Object Oriented ideas [2,3]. 2 In this wide research space, the concept of contextual programming first proposed in [4] later refined in [5] and implemented in [6] does assume a rather intermediate position. In fact, contextual languages do not force a specific program structuring model: rather, since the notion of ....

M. Bugliesi, A declarative view of inheritance in Logic Programming, Computer Sciences, Purdue University (November 1991).

....front to develop a deductive objectoriented language by taking an object oriented view and actually incorporating features peculiar to this paradigm. In the last few years, several proposals also addressed the issue of a direct semantics for logic based object oriented languages, for example [6, 13, 14]. These proposals attempt to provide a higher level abstraction for the object oriented features such as objects, classes, subclasses, methods, inheritance, overriding, encapsulation, etc. They also recognize the fact that implication and negation are not the answer to the problem of subclass ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....5.2 Operational Semantics In this section, we discuss the operational semantics of MultiLog by presenting a goal directed sequent style proof system. This style of proof systems has also been adopted in languages such as Miller s module language [20] Contextual Logic Programming [21] SelfLog [3], ORLog [15] etc. The proof system is defined as a set of properties for the two proof predicates and . This structure essentially gives rise to a two tier proof system. The proof relation defines the provability of non b atoms in general and defines the provability of b atoms in one ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....v) 2 S and l 0 l 5 Note that b atoms are not part of the Herbrand base H as their satisfaction really depends upon the interpretations and an entailment function . But note that the data components of b atoms, the corresponding m atoms, are. 6 The term T interpretation is borrowed from [2]. 3.2 Belief in Herbrand Sets as Parametric Inheritance Let us revisit De nition 3.1 introduced in section 3, and discuss how it is reminiscent of the concept of parametric inheritance before we present the notions of interpretation structures and formula satisfaction for MultiLog databases. ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113-130. The MIT Press, 1992.

....proposed in the literature to define structured logic languages more coherent with the logic paradigm. These proposals cover a wide space, ranging from the conventional notion of scope rule and block based programming [GMR88] to the integration into the logic framework of ObjectOriented ideas [BR91,B91]. In this wide research space, the concept of contextual programming first proposed in [MP89] and later refined in [MNR89] and implemented in [LMN89] does assume a rather intermediate position. In fact, contextual languages do not force a specific program structuring model: rather, since the ....

M. BUGLIESI, A declarative view of inheritance in Logic Programming, Computer Sciences, Purdue University, November 1991.

....has been used and appreciated most widely. Overriding has been a difficult issue to address in logic, as it is related to negation, belief or theory revision, and non monotonic reasoning. Several approaches were appealing in modeling overriding in knowledge representation and in knowledge bases [9, 38, 11, 4, 26, 8, 35, 6, 22, 5, 31, 5, 2, 3, 29, 28, 39, 13, 14, 30, 19]. Most solutions were computationally expensive, or were heavily dependent on the user for capturing the intended semantics i.e, inheritance was almost hand coded into the program. In the latter case, logic did very little in capturing the spirit of overriding and thus, was error prone. ....

....have been different. 2 4 Proof Theory In this section, we develop a proof procedure in order to assign operational semantics to programs in our language. We present a goal directed sequent style proof system similar to Miller s module language [27] Contextual Logic Programming [28] Selflog [5], ORLog [19] etc. The proof system is defined as a set of properties for the proof predicate . In this proof system, goals are proven in the context of a pair of objects, called the initial context and the current context (generally called the context or the context pair) The purpose of ....

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M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....of a subtype. Interestingly, although we include typing, inheritance, overriding, functional and multivalued methods in Gulog, the results in this chapter are similar to those for Datalog with negation. The semantics of deductive object oriented logics have been defined in a similar way in [4, 27, 65, 73]. Unlike these approaches, we use a different definition of model, claiming that it describes a natural description of programs and has an interesting and useful theory associated with it. Also in [4] there is no concept of inheritance or overriding. In the definition of the perfect model of an ....

....with equivalence predicates and inheritance, and take the perfect model of the augmented program. Unlike our approach, inheritance and overriding are not dealt with in the definition of model. Also if there are conflicts due to multiple inheritance, a program may have multiple perfect models. In [27], the authors consider interpretations of units of a program and combine them to give an interpretation of the program. The model of a program is regarded as a function over Herbrand sets rather than a simple Herbrand set. Our approach considers the program as a single unit. Laenens and Vermiers ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Joint International Conference and Symposium on Logic Programming, pages 113--127. MIT Press, 1992.

.... then required to deal with inheritance conflicts and as a consequence may have to settle for multiple minimal models at the declarative level, e.g. as in [47] Current solutions that are proposed in the literature are based on non monotonic reasoning [74] stratification [22] program composition [20, 61, 62], etc. These proposals have been criticized due to the skepticism about their feasibility as an efficient computational platform. Behavioral inheritance has been studied in deductive formalisms like the Ordered Theories of [50] in modular languages such as Contextual Logic Programming [61, 62] ....

....to Behavioral Inheritance There are several important differences between our language and others . Behavioral inheritance has been studied in the context of Ordered Theories [50] Contextual Logic Programming [61, 62] artificial intelligence, non monotonic reasoning, and a few others such as [20, 22], to name a few. Research in artificial intelligence and nonmonotonic reasoning is mainly concerned with inheritance of properties and conflicts, and do not consider behaviors and structures of objects. Some of the proposals also 94 sacrifice completeness, or are highly non deterministic. The ....

[Article contains additional citation context not shown here]

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....model semantics for programs with negation. Finally we define a bottom up procedure that computes the unique stable model of a stratified program. 1 Introduction There have been several attempts at combining inheritance with deductive programming languages within clean mathematical settings [1, 2, 3, 5, 6, 8, 9, 10, 11, 12, 13, 14]. Inheritance is an essential concept in AI and in object oriented programming that comprises two main aspects: structural and behavioral inheritance. Structural inheritance is a mechanism for propagating method declarations and signatures from classes to their subclasses or instances. Behavioral ....

....the proposal in [8] achieved this functionality at the expense of the loss of dynamic subclassing capability. Behavioral inheritance has been studied also in deductive formalisms like the Ordered Theories of [11] in modular languages such as Contextual Logic Programming [13, 14] SelfLog [3] and several others. In these proposals, an object is viewed as a set of rules (clauses) that represent the properties that hold at that object. Hence, although the functionalities of inheritance are the same as in object oriented systems, the resulting languages are essentially modular languages ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....inheritance. We are then required to deal with inheritance conflicts and as a consequence may have to settle for multiple minimal models at the declarative level, e.g. as in [13] Current solutions that are proposed in the literature are based on non monotonic reasoning [20] program composition [3], etc. These proposals have been criticized due to the skepticism about their feasibility as an efficient computational platform. Behavioral inheritance has been studied in deductive formalisms such as Ordered Theories [14] in logic languages such as LIFE [1] and several others. L O [16] on the ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....also enables to define modules as open environments, so that proving the query [m 1 ] m 2 ]G amounts to prove the goal G in the composition of modules m 1 and m 2 . Languages providing modularity features of this kind have been presented in [36, 38] Also, a similar point of view has been taken in [10], where a declarative characterization of inheritance is defined, and in [31] where an extension of logic programming is proposed to capture the main features of object oriented programming. When a module is regarded as being open, it is allowed to export some information to the external ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Join Int. Conf. and Symp. on Logic Programming, pages 113--127, Washington, 1992. MIT Press.

....of objects in a goal (i.e. special switching goals u:G are considered here, where u is an object(theory) name and G a goal) to switch from an object to another during the computation. Following this idea a number of improvements have been proposed. Among these we mention the language SelfLog, [15], where programs are divided into collections of units organized into inheritance hierarchies, whose semantics is defined, by overriding. Thus, a unit u inherits only the predicate definitions in its super classes, which are not defined in u itself. It is also important to mention, Contextual ....

M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In Joint International Conference and Symposium on Logic Programming, pages 112--127, 1992.

....example, the notion of composition among programs is inherently different from the notion of cooperation through message passing among objects. Therefore, in order to model the cooperation among objects, we consider an approach similar to the one introduced for object based logic programming in [14], for the ObjectLog language. This approach is based on the use of a composite structure for interpretations in which all the objects are interpreted simultaneously. In this approach an interpretation for a database O GammaDB = obj 1 ; obj s is defined as the tuple of sets hI(obj 1 ) ....

M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In K.R. Apt, editor, Proc. Joint Int'l Conf. and Symp. on Logic Programming, pages 113--127, 1992.

....operator is obtained in [2] Static and dynamic extension overriding mechanisms can be expressed using the generalized operator. Since the semantic domains are (equivalence classes of) clauses we have a uniform treatment of static and dynamic inheritance, which in other compositional semantics [7] require different semantic objects to coexist. The semantics in [2] is the first compositional semantics of units and inheritance which correctly models computed answer substitutions. iv) Our framework is strongly related to abduction [10] If Omega is the set of abducible predicates, the ....

M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In K. Apt, editor, Proc. Joint Int'l Conf. and Symposium on Logic Programming. The MIT Press, Cambridge, Mass., 1992.

....is that the definition of inheritance assumed in that paper is based only on the idea of extension rather than overriding between inherited definitions. This assumption is crucial in the definition of semantic framework presented in [7] A compositional semantics of inheritance is also given in [8], but different semantic objects (the least Herbrand model and the immediate consequence operator respectively) are required to coexist there, in order to capture the meaning of static and dynamic inheritance. In contrast to that case, the choice of context sensitive interpretations, allows us to ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....rules more refined than those effecting the language of [71] On similar grounds, a non monotonic interpretation of implication led Monteiro and Porto to introduce the context extension operator of [78] as the foundation for Contextual Logic Programming. Similarly, messages were proposed [62, 13, 19] as a way to achieve a logical reinterpretation for some of the distinguishing features of the Object Oriented programming paradigm. Later extensions to the framework of [71] led Miller and his colleagues [70, 85] and, independently, Shapiro and Moscowitz [82] to study other (higher order) ....

....formulas derivable in Q may be no longer derivable in the composition of P Q. For the two programs above, p(1) is derivable from Q whereas it is not so from P Q. The composition of two programs can be expressed in terms of the programs denotation using the following operator introduced in [19]. 8 Definition 2.1. Let be an arbitrary set of predicate symbols and let S 1 and S 2 be two elements of P(B) Then the function 3 : P(B) Theta P(B) 7 P(B) is defined as follows: S 1 3 S 2 = S 1 [ ft 2 S 2 j P red(t) 62 g This definition is used in [19] to show that 3 is continuous ....

[Article contains additional citation context not shown here]

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

....looked at as an independent fragment to be arbitrarily composed onto any hierarchy. Then the compositional properties of our semantics ensure that the meaning of the resulting hierarchy can be determined from the meaning of the components. A compositional semantics of inheritance is also given in [6], but different semantic objects (the least Herbrand model and the immediate consequence operator respectively) are required to coexist there, in order to capture the meaning of static and dynamic inheritance. In contrast to that case, the choice of context sensitive interpretations, allows us to ....

M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In K. Apt, editor, Proc. Joint Int'l Conf. and Symposium on Logic Programming. The MIT Press, Cambridge, Mass., 1992.

....in this paper. Again, the difference is that their semantics framework applies to complete hierarchies, like our model theoretic semantics, but there is no attempt to give any formal account of compositionality. A compositional semantics of inheritance with overriding is also proposed in [10], but different semantic objects (the least Herbrand model and the immediate consequence operator respectively) are required to coexist there, in order to capture the meaning of static and dynamic inheritability. In contrast to that case, the choice of context sensitive interpretations, allows us ....

M. Bugliesi. A declarative view of inheritance in logic programming. In K. Apt, editor, Proc. Joint Int. Conference and Symposium on Logic Programming, pages 113--130. The MIT Press, 1992.

No context found.

M. Bugliesi. A declarative view of inheritance in logic programming. In Krzysztof Apt, editor, Proceedings of the Joint International Conference and Symposium on Logic Programming, pages 113-- 127, Washington, USA, 1992. The MIT Press.

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M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In Proc. of the Joint International Conference and Symposium on Logic Programming, 1992.

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M. Bugliesi. A declarative view of inheritance in logic programming. In Proceedings of the Joint International Conference and Symposium on Logic Programming, 1992.

No context found.

M. Bugliesi. A declarative view of inheritance in logic programming. In Krzysztof Apt, editor, Proceedings of the Joint International Conference and Symposium on Logic Programming, pages 113-127, Washington, USA, 1992. The MIT Press. 8

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M. Bugliesi. A Declarative View of Inheritance in Logic Programming. In K. Apt, editor, Proc. of the Join International Conference and Symposium on Logic Programming, JICSLP'92, pages 113--127, Washington, 1992. The MIT Press.

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