Results

**11 - 15**of**15**### Extended Horn Clauses: the Framework and some Semantics

, 1991

"... The purpose of this paper is twofold: to introduce a new extension of concurrent logic programming languages aiming at handling synchronicity and to present and compare several semantics for it. The extended framework essentially rests on an extension of Horn clauses, including multiple atoms in the ..."

Abstract
- Add to MetaCart

The purpose of this paper is twofold: to introduce a new extension of concurrent logic programming languages aiming at handling synchronicity and to present and compare several semantics for it. The extended framework essentially rests on an extension of Horn clauses, including multiple atoms in their heads and a guard construct, as well as a new operator between goals. The semantics discussed consist of four semantics. They range in the operational, declarative and denotational types and are issued both from the logic programming tradition and the imperative tradition. They are composed of an operational semantics, describing the (classical) success set and failure set, of two declarative semantics, extending the Herbrand interpretation and the immediate consequence operator to the extended framework, and of a denotational semantics, defined compositionally and on the basis of histories possibly involving hypothetical statements. The mathematical tools mainly used are complete lattice...

### The Semantics of the Combination of Atomized Statements and Parallel Choice

, 1998

"... . In this paper we define a uniform language L that is an extension of the language underlying the process algebra PA. One of the main extensions of this language over PA is given by so-called atomizing brackets. If we place these brackets around a statement then we treat this statement as an atomic ..."

Abstract
- Add to MetaCart

. In this paper we define a uniform language L that is an extension of the language underlying the process algebra PA. One of the main extensions of this language over PA is given by so-called atomizing brackets. If we place these brackets around a statement then we treat this statement as an atomic action. Put differently, these brackets remove all interleaving points. We present a transition system for the language and derive its operational semantics. We show that there are several options for defining a transition system such that the resulting operational semantics is a conservative extension of the semantics for PA. We define a semantic domain and a denotational model for the language. Next we define a closure operator on the semantic domain and show how to use this closure operator to derive a fully abstract denotational semantics. Then the algebraic theory of the language is considered. We define a collection of axioms and a term rewrite system based on these axioms. Using this...

### On the Semantics of Atomized Statements - the Parallel-Choice option (Extended Abstract)

"... Several semantics are given for a language L that has as its main feature so-called atomizing brackets: if we place these brackets around a statement then we treat this statement as an atomic action. We point out that there are several options for giving semantics and we choose (inspired by conc ..."

Abstract
- Add to MetaCart

Several semantics are given for a language L that has as its main feature so-called atomizing brackets: if we place these brackets around a statement then we treat this statement as an atomic action. We point out that there are several options for giving semantics and we choose (inspired by concurrent logic languages) one option (the socalled parallel-choice option). We provide the operational intuition with a transition system for this language from which we derive operational semantics. The main results of this paper are two compositional semantics for L based on sequences of actions that are able to model deadlock and divergence, respectively. We have that the denotational semantics for the deadlock behavior is correct w.r.t. the operational semantics. 1 Introduction In this paper we study the semantics of a programming language that has as operational features 1. A unary operator h\Deltai, called atomizer, that turns its argument into its atomic version. In the prese...

### Comparative semantics of µLog

, 1992

"... . The paper aims at a semantic study of the integration of blackboards in logic programming. To that end, a new logic programming framework involving Lindalike primitives is proposed first. It is dedicated to no particular logic language but rather focuses on the key concepts and control operators. ..."

Abstract
- Add to MetaCart

. The paper aims at a semantic study of the integration of blackboards in logic programming. To that end, a new logic programming framework involving Lindalike primitives is proposed first. It is dedicated to no particular logic language but rather focuses on the key concepts and control operators. As natural consequences, it subsumes existing concrete proposals ([2, 4, 5]) and provides a general framework well-suited for their semantic analysis. Five semantics are described and compared. They range in the operational, declarative and denotational types and are issued both from the logic programming and the imperative traditions. They are composed of two operational semantics, describing respectively the success/failure sets, and various failures, of two declarative semantics, extending the classical Herbrand interpretation and immediate consequence operator, and of one denotational semantics, defined compositionally and on the basis of process-like histories. The mathematical tools ma...

### Comparative Metric Semantics for Commit in Or-Parallel Logic Programming

- In Proceedings of the International Logic Programming Symposium 97
, 1997

"... For the control flow kernel of or-parallel Prolog with commit an operational and a denotational model are constructed and related using techniques from metric semantics. By maintaining explicit scope information a compositional handling of the commit for the denotational model is established. By app ..."

Abstract
- Add to MetaCart

For the control flow kernel of or-parallel Prolog with commit an operational and a denotational model are constructed and related using techniques from metric semantics. By maintaining explicit scope information a compositional handling of the commit for the denotational model is established. By application of an abstraction function, which deletes this extra information, the operational semantics is recovered. 1