Panos Rondogiannis

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We give a purely model-theoretic characterization of the semantics of logic programs with negation-as-failure allowed in clause bodies. In our semantics, the meaning of a program is, as in the classical case, the unique <i>minimum</i> model in a program-independent ordering. We use an expanded truth domain that has an uncountable linearly ordered set of(More)
The purpose of this paper is to demonstrate that first-order functional programs can be transformed into intensional programs of nullary variables, in a semantics preserving way. On the foundational side, the goal of our study is to bring new insights and a better understanding of the nature of functional languages. From a practical point of view, our(More)
We propose a purely extensional semantics for higher-order logic programming. In this semantics program predicates denote sets of ordered tuples, and two predicates are equal iff they are equal as sets. Moreover, every program has a unique minimum Herbrand model which is the greatest lower bound of all Herbrand models of the program and the least(More)
We present an infinite-game characterization of the well-founded semantics for functionfree logic programs with negation. Our game is a simple generalization of the standard game for negationless logic programs introduced by van Emden [M.H. van Emden, Quantitative deduction and its fixpoint theory, Journal of Logic Programming 3(1):37–53, 1986] in which two(More)
Extensional higher-order logic programming has been introduced as a generalization of classical logic programming. An important characteristic of this paradigm is that it preserves all the well-known properties of traditional logic programming. In this paper we consider the semantics of negation in the context of the new paradigm. Using some recent results(More)
We present a fixed point theorem for a class of (potentially) non-monotonic functions over specially structured complete lattices. The theorem has as a special case the KnasterTarski fixed point theorem when restricted to the case of monotonic functions and Kleene’s theorem when the functions are additionally continuous. From the practical side, the theorem(More)
In this paper we introduce the logic programming languageDisjunctive Chronolog which combines the programming paradigms of temporal and disjunctive logic programming. Disjunctive Chronolog is capable of expressing dynamic behaviour as well as uncertainty, two notions that are very common in a variety of real systems. We present the minimal temporal model(More)
We present a purely model-theoretic semantics for disjunctive logic programs with negation, building on the infinite-valued approach recently introduced for normal logic programs [11]. In particular, we show that every disjunctive logic program with negation has a nonempty set of minimal infinite-valued models. Moreover, we show that the infinite-valued(More)