Recursive programs and denotational semantics in absolute logics of programs

Operational and Denotational Semantics of Rewrite Programs

In this paper we present a new operational and denotational semantics for rewrite systems as logic programs. The main feature of our rewrite programs is that they allow us to define predicates not only by implications as in Prolog, but also by equivalences. We give a few examples showing how rewrite programs may turn out to be more effective than Prolog programs in capturing the user’s intended...

Denotational Semantics for "Natural" Language Question-Answering Programs

Scott-Strachey style denotational semantics is proposed as a suitable means of communicating the specification of "natural" language question answerers to computer programmers and software engineers. The method is exemplified by a simple question answerer communicating with a small data base. This example is partly based on treatment of fragments of English by Montague. Emphasis is placed on th...

Computing and Comparing Semantics of Programs in Multi-valued Logics

The different semantics that can be assigned to a logic program correspond to different assumptions made concerning the atoms whose logical values cannot be inferred from the rules. Thus, the well founded semantics corresponds to the assumption that every such atom is false, while the Kripke-Kleene semantics corresponds to the assumption that every such atom is unknown. In this paper, we propos...

Computing and Comparing Semantics of Programs in Four-Valued Logics

Recursive Aggregates in Disjunctive Logic Programs: Semantics and Complexity

The addition of aggregates has been one of the most relevant enhancements to the language of answer set programming (ASP). They strengthen the modeling power of ASP, in terms of concise problem representations. While many important problems can be encoded using nonrecursive aggregates, some relevant examples lend themselves for the use of recursive aggregates. Previous semantic definitions typi...