A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....of the operators of the algebra. Logic programming is extended with modularization constructs without any need to extend the language of Horn clauses. Module composition is indeed an inherently meta linguistic mechanism. The compositional frameworks of Mancarella and Pedreschi [46] Brogi et al. [26, 25] as well as open logic programs [22] and differential logic programming [21] can be seen as different formulations of this idea. Mechanisms for information hiding and encapsulation, based on this notion of module composition, have been adopted by prototypical implementations, such as the GSdel ....

A. Brogi, E. Lamina, and E. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1), 1992.

.... we consider the case in which we close (or dually, open) the definition of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open definition for the predicate p, can be composed in the sense of [17] Also in [2] and further in [3], the compositionality of normal logic programs is studied. In [3] a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modelled by the composition of the admissible Herbrand models of the programs. These results, together with ....

....of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open definition for the predicate p, can be composed in the sense of [17] Also in [2] and further in [3] the compositionality of normal logic programs is studied. In [3], a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modelled by the composition of the admissible Herbrand models of the programs. These results, together with the results of [2] which we mentioned above) provide normal logic ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-Theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

.... we consider the case in which we close (or dually, open) the de nition of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open de nition for the predicate p, can be composed in the sense of [17] Also in [2] and further in [3], the compositionality of normal logic programs is studied. In [3] a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modeled by the composition of the admissible Herbrand models of the programs. These results, together with ....

....nition of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open de nition for the predicate p, can be composed in the sense of [17] Also in [2] and further in [3] the compositionality of normal logic programs is studied. In [3], a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modeled by the composition of the admissible Herbrand models of the programs. These results, together with the results of [2] which we mentioned above) provide normal logic ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-Theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1-21, 1992.

....different semantic interpretations of logic programs. For example, one interesting issue is compositionality. Having a compositional semantic framework is indeed very convenient for formal reasoning on program properties and can facilitate the development of modular programs (Bossi et al. 1994a; Brogi et al. 1992; Gaifman Shapiro, 1989; Mancarella Pedreschi, 1987) We sketch here the main ideas concerning the role played by contexts in reduction systems, but for a more precise overview we invite the interested reader to join us in the little detour, from the logic programming world to the process ....

Brogi, A., Lamma, E., & Mello, P. (1992). Compositional model-theoretic semantics for logic programs. New generation computing, 11(1), 1--21.

....This idea gave way to the development of several proposals of modular systems based on the idea of program composition. The approach discussed by Bossi et al. in [3, 4] together with the compositional frameworks of Mancarella and Pedreschi ( 21] Gaifman and Shapiro ( 14] and of Brogi et al. [6] can in fact be seen as different formulations of this idea. The novelty of the proposal presented in this paper is in the type of composition mechanisms we have considered as well as in the domain chosen for the semantic characterization. The isa composition of differential programs provides a ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1), 1992.

....the language of program expressions encompass encapsulation as a unary operation over a program expression. A program expression can be a plain logic program or a synthesis of logic programs. Encapsulation substitutes a program expression with its least Herbrand model. This approach is similar to [BLM92] where a program is visible from other programs only through its logical consequences. In this paper, we introduce structure into units that allows information hiding. Each unit consists of two parts, a public part and a private part. Information from the public part is visible to other units ....

A. Brogi, E. Lamma, and P. Mello. Compositional model--theoretic semantics for logic programs. New Generation Computing, 11:1--21, 1992.

.... while the static version (that we can call s ) is got by defining the combination of interpretation transformers in the following way TP s M Q (I) TP (I) fi F M TQ which corresponds with the operator based definition P s M Q = P M Q , where Q is the closure operator of [BLM92]. 4 Operational Semantics Before we give the operational semantics of tuple inheritance, we reformulate CLP operational semantics specifying the concrete program P where we look for clauses. We assume the existence of a selection rule R used to decide the atom to be solved in a goal. Later, we ....

A. Brogi, E. Lamma, P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1-21,1992.

.... we consider the case in which we close (or dually, open) the definition of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open definition for the predicate p, can be composed in the sense of [19] Also in [3] and further in [4], the compositionality of normal logic programs is studied. In [4] a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modelled by the composition of the admissible Herbrand models of the programs. These results, together with ....

....of only one predicate (and possibly more) Concerning theory composition, we argued that, two theories, which both have an open definition for the predicate p, can be composed in the sense of [19] Also in [3] and further in [4] the compositionality of normal logic programs is studied. In [4], a compositional model theoretic semantics for positive logic programs is presented, where the composition of programs is modelled by the composition of the admissible Herbrand models of the programs. These results, together with the results of [3] which we mentioned above) provide normal logic ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-Theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

....to make it suitable for modular programming but do not investigate the knowledge representation qualities of the resulting logic. An exception is [16] which studies the compositionality problem in the context of Disjunctive Logic Programming. In some studies in modular logic programming e.g. [7], 3] compositionality of the logic is seen as a first rank requirement; the semantics of the (syntactical) composition of modules is required to be the result of a semantical composition operator on the semantics of the modules. The semantic composition operator under study here is the logical ....

....P depend on atoms defined in Q (the program Q is in fact a conservative extension of the program P ) By allowing predicates to be open in a logic program, we deal with incomplete knowledge on predicates. In [12] import predicates are introduced to represent this kind of incomplete knowledge. In [7], 6] they work with a different notion of open predicates to capture the possible composition with other programs. Their semantics of admissable Herbrand models for definite programs is suited for compositionality problems, but seems less suitable for knowledge representation. In [5] this ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-Theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

.... while the static version (that we can call s ) is got by defining the combination of interpretation transformers in the following way T P s M Q (I) T P (I) fi M M P which corresponds with the operator based definition P s M Q = P M Q 3 , where Q 3 is the closure operator of [BLM92]. 4 Operational Semantics Before we give the operational semantics of tuple inheritance, we reformulate CLP operational semantics specifying the concrete program P where we look for clauses. The rule to compute a goal G is: G = c; D 1 ; D j ; D r A P c 0 ; D 1 ; B 1 ....

A. Brogi, E. Lamma, P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1-21,1992.

.... have been proposed; to the best of our knowledge, the first papers to discuss various forms of compositional semantic characterizations of definite logic programs were the ones of Lassez and Maher [LM84, Mah88] further work has been done by Mancarella and Pedreschi [MP88] and Brogi et al. BLM92] In [GS89] Gaifman and Shapiro proposed a compositional semantics, which was further extended in [BGLM94] and for CLP programs in [GDL95] Compositionality vs. non monotonicity. However, in the development of semantics for normal logic programs, logic programs which employ the negation ....

....mechanisms, an approach which originated with the work of Miller [Mil86, Mil89] Moreover, meta linguistic operations are quite powerful. For instance, the compositional systems of Mancarella and Pedreschi [MP88] Gaifman and Shapiro [GS89] Bossi et al. BBG 93] and Brogi et al. BLM92, BMPT90] can be seen as different instances of this idea. Furthermore, the typical mechanisms of the objectoriented paradigm, such as encapsulation and information hiding, as well as more complex form of composition mechanisms in which we may distinguish between imported, exported, and local ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

.... few semantics have been proposed; to the best of our knowledge, the first papers to discuss various forms of compositional semantic characterizations of definite logic programs were the ones of Lassez and Maher [18, 20] further work has been done by Mancarella and Pedreschi [22] and Brogi et al. [4]. In [12] Gaifman and Shapiro proposed a compositional semantics, which was further extended in [3] and for CLP programs in [11] Compositionality vs. non monotonicity. However, in the development of semantics for normal logic programs, which employ the negation operator) compositionality ....

....extend programs by linguistic mechanisms, an approach which originated with the work of Miller [23, 24] Moreover, meta linguistic operations are quite powerful. For instance, the compositional systems of Mancarella and Pedreschi [22] Gaifman and Shapiro [12] Bossi et al. 2] and Brogi et al. [4, 5] can be seen as different instances of this idea. Furthermore, the typical mechanisms of the object oriented paradigm, such as encapsulation and information hiding, as well as more complex form of composition mechanisms in which we may distinguish between imported, exported, and local (hidden) ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

....forms of encapsulation and information hiding. Several proposals in the literature follow this approach to modular logic programming. The open programs introduced by Bossi et al. in [6] the modular frameworks of Mancarella and Pedreschi [17] Gaifman and Shapiro [12] and of Brogi et al. [8] can in fact be seen as different formulations of this idea. Our paper contributes to this line of research. Building on the idea of constructing programs by composition, we consider a novel and general composition operator that is amenable to several specializations. The semantics of this ....

....proposals in the literature follow an approach to modular programming based on program composition. We already mentioned the open programs introduced by Bossi et al. in [6] the modular frameworks of Mancarella and Pedreschi [17] Gaifman and Shapiro [12] and of Brogi, Lamma and Mello in [8]. The novelty of our proposal is in the type of composition mechanisms we have considered as well as in the domain chosen for the semantic characterization. Our composition operator provides a uniform semantics for the composition mechanisms proposed in the existing approaches and extends them ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1), 1992.

....steadfast program is an open Sigma program. The semantics of an open program P is given by the j models j P and j P Gamma , and steadfastness in a framework F = h Sigma; Ii intuitively means parametric correctness. Open logic programs have been considered by Brogi, Lamma and Mello. In [3], they introduce Admissible Herbrand Models, to provide a model theoretic semantics for program composition. Admissible models can be seen as a particular case of j models, where only suitable Herbrand pre interpretations j are considered. By contrast, in our approach, we place no restriction on ....

....Admissible models can be seen as a particular case of j models, where only suitable Herbrand pre interpretations j are considered. By contrast, in our approach, we place no restriction on j, since we need to compare j models with the interpretations of an arbitrary framework. That is, whereas [3] is concerned with a model theoretic semantics for program composition, our primary goal is open correctness in a class of interpretations. Modularity is a by product of steadfastness, since the latter is preserved by composition. Moreover, allowing arbitrary pre interpretations yields a ....

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A. Brogi, E. Lamma and P. Mello. Compositional model--theoretic semantics for logic programs. New Generation Computing 11:1-21, 1992.

....and implemented systems (see [6] for a survey) Two of the key issues when defining a modular logic language are expressive power and efficiency. From the language design point of view, modularity in logic programming has been conceived along two orthogonal lines of research. Some proposals [20, 14, 10, 1, 4] have focused primarily on the issue of . In this first approach, module composition is a mechanism: modules are viewed as sets of Horn clauses and their (algebraic) composition is modeled in terms of various operations on the component clauses (e.g. union) The other approach (see [11, 17, 18, ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. , 11(1):1--21, 1992.

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A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

....be determined by the least Herbrand models of its clauses. To tackle this problem, several compositional semantics for logic programs have been studied by using higher order semantics [Fitting 1987; Lassez and Maher 1984; Maher 1988; Mancarella and Pedreschi 1988; O Keefe 1985] Herbrand models [Brogi et al. 1992] and notions such as full abstraction [Gaifman and Shapiro 1989] A number of different approaches to modularizing logic programming have also been proposed. Some of them augment logic programming with constructs for declaring and using modules, much in the spirit of conventional programming ....

....in Section 5, where the extended algebra of modules is presented. Modular Logic Programming Delta 7 2. 2 Metalogical implementation In this section, we present a simple interpretation oriented implementation of the language of program expressions, which is extensively described in [Brogi 1993; Brogi et al. 1992]. Program composition operations may be naturally implemented by means of metalogic. Metalevel compositions of programs are realized by a metainterpreter which combines separate programs at the metalevel. The metalogical definition of program composition operations is obtained by adding new ....

Brogi, A., Lamma, E., and Mello, P. 1992. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing 11, 1, 1--21.

....programs, that is, logic programs with negation by default presented in [20] The starting point is the characterization of the supported interpretations for definite, ground programs. The concept of supported interpretations adopted here is inherited from a similar concept first introduced in [22] and then exploited in [20] In [22] supported interpretations are used to provide an alternative characterization of the standard Herbrand interpretations of a definite logic 5 program, which provides a compositional model theoretic semantics of logic programs (see also section 6) The notion ....

....with negation by default presented in [20] The starting point is the characterization of the supported interpretations for definite, ground programs. The concept of supported interpretations adopted here is inherited from a similar concept first introduced in [22] and then exploited in [20] In [22] supported interpretations are used to provide an alternative characterization of the standard Herbrand interpretations of a definite logic 5 program, which provides a compositional model theoretic semantics of logic programs (see also section 6) The notion of supported interpretation that we ....

[Article contains additional citation context not shown here]

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. In New Generation Computing, 11(1):1--21. Springer-Verlag, 1992.

....of Horn clauses and their algebraic composition is modeled in terms of various operations on the component clauses: union, deletion, closure and combination of the above. The compositional frameworks of Mancarella and Pedreschi [61] Gaifman and Shapiro [39] Bossi et al. 8] and of Brogi et al. [15, 12] can in fact be seen as different formulations of this idea. Information hiding and encapsulation can also be accounted for in this framework quite elegantly. Algebraic program composition can be made more selective so as to distinguish, within a module, predicates to be imported from other ....

....the former can exploit the latter (and vice versa) to derive new knowledge. 2.1.2. Closure. There are situations in which it might be useful to view a program as closed (as opposed to open) with respect to possible compositions with other programs. This situation is discussed by Brogi et al. in [12], where the authors introduce a closure operator which enforces a form closed world assumption on the programs of their algebra. Roughly, the application of the closure operator to a program makes that program visible to other programs only in terms of its logical consequences (its extensional ....

A. Brogi, E. Lamma, and P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1--21, 1992.

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A. Brogi, E. Lamma, P. Mello. Compositional Model-theoretic Semantics for Logic Programs. New Generation Computing, 11(1):1-21,1992.

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Antonio Brogi, Evelina Lamma, and Paola Mello. 1992. Compositional model-theoretic semantics for logic programs. New Generation Computing, 11:1--21.

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Antonio Brogi, Evelina Lamma, and Paola Mello. 1992. Compositional model-theoretic semantics for logic programs. New Generation Computing, 11:1--21.

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Brogi, A., Lamma, E., Mello, P., Compositional model-theoretic semantics for logic programs, New Generation Computing 11:1-21 (1992).

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