Singular and Plural Functions for Functional Logic Programming

Functional logic programming (FLP) languages use non-terminating and non-confluent constructor systems (CS's) as programs in order to define non-strict non-determi-nistic functions. Two semantic alternatives have been usually considered for parameter passing with this kind of functions: call-time choice and run-time choice. While the former is the standard choice of modern FLP languages, the latter lacks some properties---mainly compositionality---that have prevented its use in practical FLP systems. Traditionally it has been considered that call-time choice induces a singular denotational semantics, while run-time choice induces a plural semantics. We have discovered that this latter identification is wrong when pattern matching is involved, and thus we propose two novel compositional plural semantics for CS's that are different from run-time choice. We study the basic properties of our plural semantics---compositionality, polarity, monotonicity for substitutions, and a restricted form of the bubbling property for constructor systems---and the relation between them and to previous proposals, concluding that these semantics form a hierarchy in the sense of set inclusion of the set of computed values. We have also identified a class of programs characterized by a syntactic criterion for which the proposed plural semantics behave the same, and a program transformation that can be used to simulate one of them by term rewriting. At the practical level, we study how to use the expressive capabilities of these semantics for improving the declarative flavour of programs. We also propose a language which combines call-time choice and our plural semantics, that we have implemented in Maude. The resulting interpreter is employed to test several significant examples showing the capabilities of the combined semantics. To appear in Theory and Practice of Logic Programming (TPLP)Comment: 53 pages, 5 figure

Measure instrumental in russian

We will argue that some seemingly adverbial free DPs in the instrumental in Russian which are traditionally termed measure instrumental are best understood as secondary predicates. We present the relevant syntactic assumptions and propose a semantics of this use of DPs in the instrumental. This proposal hears on the distinction between adjunct modification and secondary predication

Adding plural arguments to Curry programs

Functional logic languages combine lazy (demand-driven) evaluation strategies from functional programming with non-deterministic computations from logic programming. To provide a strategy-independent semantics, most languages are based on the call-time choice semantics where parameters are passed as values. From an implementation point of view, the call-time choice semantics fits well with sharing performed by lazy languages. On the other hand, there are also situations where it is intended to pass non-deterministic arguments as sets of values in order to exploit the power of non-deterministic programming. This alternative parameter passing model is known under the name "plural" arguments. In this paper, we show how both mechanisms can be integrated in a single language. In particular, we present a novel technique to implement plural arguments in a call-time choice language so that existing implementations of contemporary functional logic languages can be easily re-used to implement plural parameter passing

Attempto - From Specifications in Controlled Natural Language towards Executable Specifications

Deriving formal specifications from informal requirements is difficult since one has to take into account the disparate conceptual worlds of the application domain and of software development. To bridge the conceptual gap we propose controlled natural language as a textual view on formal specifications in logic. The specification language Attempto Controlled English (ACE) is a subset of natural language that can be accurately and efficiently processed by a computer, but is expressive enough to allow natural usage. The Attempto system translates specifications in ACE into discourse representation structures and into Prolog. The resulting knowledge base can be queried in ACE for verification, and it can be executed for simulation, prototyping and validation of the specification.Comment: 15 pages, compressed, uuencoded Postscript, to be presented at EMISA Workshop 'Naturlichsprachlicher Entwurf von Informationssystemen - Grundlagen, Methoden, Werkzeuge, Anwendungen', May 28-30, 1996, Ev. Akademie Tutzin

Tagungsband zum 21. Kolloquium Programmiersprachen und Grundlagen der Programmierung

Das 21. Kolloquium Programmiersprachen und Grundlagen der Programmierung (KPS 2021) setzt eine traditionelle Reihe von Arbeitstagungen fort, die 1980 von den Forschungsgruppen der Professoren Friedrich L. Bauer (TU München), Klaus Indermark (RWTH Aachen) und Hans Langmaack(CAU Kiel) ins Leben gerufen wurde.Die Veranstaltung ist ein offenes Forum für alle interessierten deutschsprachigen Wissenschaftlerinnen und Wissenschaftler zum zwanglosen Austausch neuer Ideen und Ergebnisse aus den Forschungsbereichen Entwurf und Implementierung von Programmiersprachen sowie Grundlagen und Methodik des Programmierens. Dieser Tagungsband enthält die wissenschaftlichen Beiträge,die bei dem 21. Kolloquium dieser Tagungsreihe präsentiert wurden, welches vom 27. bis 29. September 2021 in Kiel stattfand und von der Arbeitsgruppe Programmiersprachen und Übersetzerkonstruktion der Christian-Albrechts-Universität zu Kiel organisiert wurde

Monadic compositional parsing with context using Maltese as a case study

Combinator-based parsing using functional programming provides an elegant, and compositional approach to parser design and development. By its very nature, sensitivity to context usually fails to be properly addressed in these approaches. We identify two techniques to deal with context compositionally, particularly suited for natural language parsing. As case studies, we present parsers for Maltese definite nouns and conjugated verbs of the first form.peer-reviewe

A Bi-Polar Theory of Nominal and Clause Structure and Function

It is taken as axiomatic that grammar encodes meaning. Two key dimensions of meaning that get grammatically encoded are referential meaning and relational meaning. The key claim is that, in English, these two dimensions of meaning are typically encoded in distinct grammatical poles—a referential pole and a relational pole—with a specifier functioning as the locus of the referential pole and a head functioning as the locus of the relational pole. Specifiers and heads combine to form referring expressions corresponding to the syntactic notion of a maximal projection. Lexical items and expressions functioning as modifiers are preferentially attracted to one pole or the other. If the head of an expression describes a relation, one or more complements may be associated with the head. The four grammatical functions specifier, head, modifier and complement are generally adequate to represent much of the basic structure and function of nominals and clauses. These terms are borrowed from X-Bar Theory, but they are motivated on semantic grounds having to do with their grammatical function to encode referential and relational meaning

Singular and plural non-deterministic parameters

The article defines algebraic semantics of singular (call-time-choice) and plural (run-time-choice) nondeterministic parameter passing and presents a specification language in which operations with both kinds of parameters can be defined simultaneously. Sound and complete calculi for both semantics are introduced. We study the relations between the two semantics and point out that axioms for operations with plural arguments may be considered as axiom schemata for operations with singular arguments