Semantics of logic programs with explicit negation

After a historical introduction, the bulk of the thesis concerns the study of a declarative semantics for logic programs. The main original contributions are: ² WFSX (Well–Founded Semantics with eXplicit negation), a new semantics for logic programs with explicit negation (i.e. extended logic programs), which compares favourably in its properties with other extant semantics. ² A generic characterization schema that facilitates comparisons among a diversity of semantics of extended logic programs, including WFSX. ² An autoepistemic and a default logic corresponding to WFSX, which solve existing problems of the classical approaches to autoepistemic and default logics, and clarify the meaning of explicit negation in logic programs. ² A framework for defining a spectrum of semantics of extended logic programs based on the abduction of negative hypotheses. This framework allows for the characterization of different levels of scepticism/credulity, consensuality, and argumentation. One of the semantics of abduction coincides with WFSX. ² O–semantics, a semantics that uniquely adds more CWA hypotheses to WFSX. The techniques used for doing so are applicable as well to the well–founded semantics of normal logic programs. ² By introducing explicit negation into logic programs contradiction may appear. I present two approaches for dealing with contradiction, and show their equivalence. One of the approaches consists in avoiding contradiction, and is based on restrictions in the adoption of abductive hypotheses. The other approach consists in removing contradiction, and is based in a transformation of contradictory programs into noncontradictory ones, guided by the reasons for contradiction

Using Problem Frames and projections to analyze requirements for distributed systems

Subproblems in a problem frames decomposition frequently make use of projections of the complete problem context. One specific use of projec-tions occurs when an eventual implementation will be distributed, in which case a subproblem must interact with (use) the machine in a projection that represents another subproblem. We refer to subproblems used in this way as services, and propose an extension to projections to represent services as a spe-cial connection domain between subproblems. The extension provides signifi-cant benefits: verification of the symmetry of the interfaces, exposure of the machine-to-machine interactions, and prevention of accidental introduction of shared state. The extension’s usefulness is validated using a case study

Unifying Requirements and Code: an Example

Requirements and code, in conventional software engineering wisdom, belong to entirely different worlds. Is it possible to unify these two worlds? A unified framework could help make software easier to change and reuse. To explore the feasibility of such an approach, the case study reported here takes a classic example from the requirements engineering literature and describes it using a programming language framework to express both domain and machine properties. The paper describes the solution, discusses its benefits and limitations, and assesses its scalability.Comment: 13 pages; 7 figures; to appear in Ershov Informatics Conference, PSI, Kazan, Russia (LNCS), 201

Requirements engineering for business workflow systems: a scenario-based approach

Workflow implementations require a deep understanding of business and human cooperation. Several approaches have been proposed to address this need for understanding, but largely in a descriptive way. Attempts to use them in software development have had mixed results. The work reported here proposes that these approaches can be used in a generative way, as part of the requirement engineering process, by (a) extending requirements engineering modelling techniques with underlying cooperation properties, (b) integrating these techniques through the use of a derivation modelling approach, and (c) providing pragmatic heuristics and guidelines that support the real-world requirements engineering practitioner to ensure a high probability of success for the business workflow system to be developed. This thesis develops and evaluates a derivation modelling approach that is based on scenario modelling. It supports clear and structured views of cooperation properties, and allows the derivation of articulation protocols from business workflow models in a scenario-driven manner. This enables requirements engineering to define how the expectations of the cooperative situation are to be fulfilled by the system to be built - a statement of requirements for business workflow systems that reflects the richness of these systems, but also acts as a feasible starting point for development. The work is evaluated through a real-world case study of business workflow management. The main contribution of this work is a demonstration that the above problems in modelling requirements for business workflow systems can be addressed by scenario-based derivation modelling approach. The method transforms models through a series of properties involving cooperation, which can be addressed by using what are effectively extensions of current requirements engineering methods

Proceedings of the 2010 Annual Conference of the Gesellschaft für Semantik

Sinn & Bedeutung - the annual conference of the Gesellschaft für Semantik - aims to bring together both established researchers and new blood working on current issues in natural language semantics, pragmatics, the syntax-semantics interface, the philosophy of language or carrying out psycholinguistic studies related to meaning. Every year, the conference moves to a different location in Europe. The 2010 conference - Sinn & Bedeutung 15 - took place on September 9 - 11 at Saarland University, Saarbrücken, organized by the Department for German Studies

Civil Procedure as a Critical Discussion

This Article develops a model for analyzing legal dispute resolution systems as systems for argumentation. Our model meshes two theories of argument conceived centuries apart: contemporary argumentation theory and classical stasis theory. In this Article, we apply the model to the Federal Rules of Civil Procedure as a proof of concept. Specifically, the model analyzes how the Federal Rules of Civil Procedure function as a staged argumentative critical discussion designed to permit judge and jury to rationally resolve litigants’ differences in a reasonable manner. At a high level, this critical discussion has three phases: a confrontation, an (extended) opening, and a concluding phase. Those phases are the umbrella under which discrete argumentation phases occur at points we call stases. Whenever litigants seek a ruling or judgment, they reach a stasis—a stopping or standing point for arguing procedural points of disagreement. During these stases, the parties make arguments that fall into predictable “commonplace” argument types. Taken together, these stock argument types form a taxonomy of arguments for all civil cases. Our claim that the Federal Rules of Civil Procedure function as a system for argumentation is novel, as is our claim that civil cases breed a taxonomy of argument types. These claims also mark the beginning of a broader project. Starting here with the Federal Rules of Civil Procedure, we embark on a journey that we expect to follow for several years (and which we hope other scholars will join), exploring our model’s application across dispute resolution systems and using it to make normative claims about those systems. From a birds-eye view, this Article also represents a short modern trek in a much longer journey begun by advocates in city states in and near Greece nearly 2500 years ago

Parallels in romance nominal and clausal microvariation

This article explores parallels in the dimensions of microvariation characterizing the functional structure and organization of the Romance nominal and clausal groups. Within a parameter hierarchy approach it is argued that observed synchronic and diachronic variation across both domains can be readily captured in terms of a single set of higher- and above all lower-level parametric options. This parallelism constitutes a welcome finding in that it points to how the available parametric space can be constrained and defined in terms of a set of common transcategorial principles and options.This is the final version of the article. It first appeared from Editura Academiei Române via http://www.lingv.ro/index.php?option=com_content&view=article&id=137%3Arrlarhiva2015&catid=36%3Areviste-ilb&Itemid=9

Desire Predicates in Presence and Absence of the Light Verbs: Addressing their Embedded Clausal Structure in Bangla

The current study focuses on an intriguing dichotomy seen in the Bangla (Bengali: Indo-Aryan) language, which centers on the desire predicates expressed by the term itʃtʃʰe ‘desire’. In the Bangla language, the desire predicate itʃtʃʰe can be used independently or in conjunction with the light verb hɔwa ‘happen’ to form the NV conjunct itʃtʃʰe hɔwa, indicating the occurrence of the desire. According to the scholarly works of Dasgupta (1989), Chatterjee (2014), and Butt (2010) the Bangla language exhibits the presence of composite verb formations, whereby a nonverb is combined with a verb. These formations involve the occurrence of a light verb with a noun, adjective, or adposition. The primary focus of this study will be on the differentiation between the bare verb itʃtʃʰe ‘desire’ and its usage in conjunction with the light verb forming itʃtʃʰe hɔwa. The distinction between them pertains to their embeddability qualities, namely the clausal complements they choose