Designing Normative Theories for Ethical and Legal Reasoning: LogiKEy Framework, Methodology, and Tool Support

A framework and methodology---termed LogiKEy---for the design and engineering of ethical reasoners, normative theories and deontic logics is presented. The overall motivation is the development of suitable means for the control and governance of intelligent autonomous systems. LogiKEy's unifying formal framework is based on semantical embeddings of deontic logics, logic combinations and ethico-legal domain theories in expressive classic higher-order logic (HOL). This meta-logical approach enables the provision of powerful tool support in LogiKEy: off-the-shelf theorem provers and model finders for HOL are assisting the LogiKEy designer of ethical intelligent agents to flexibly experiment with underlying logics and their combinations, with ethico-legal domain theories, and with concrete examples---all at the same time. Continuous improvements of these off-the-shelf provers, without further ado, leverage the reasoning performance in LogiKEy. Case studies, in which the LogiKEy framework and methodology has been applied and tested, give evidence that HOL's undecidability often does not hinder efficient experimentation.Comment: 50 pages; 10 figure

Connexive logics. An overview and current trends

In this introduction, we offer an overview of main systems developed in the growing literature on connexive logic, and also point to a few topics that seem to be collecting attention of many of those interested in connexive logic. We will also make clear the context to which the papers in this special issue belong and contribute

Warsaw Argumentation Week (Waw 2018) Organised by the Polish School of Argumentation and Our Colleagues from Germany and the UK, 6th-16th September 2018

In September 2018, the ArgDiaP association, along with colleagues from Germany and the UK, organised one of the longest and most interdisciplinary series of events ever dedicated to argumentation - Warsaw Argumentation Week, WAW 2018. The eleven-day ‘week’ featured a five day graduate school on computational and linguistic perspectives on argumentation (3rd SSA school); five workshops: on systems and algorithms for formal argumentation (2nd SAFA), argumentation in relation to society (1st ArgSoc), philosophical approaches to argumentation (1st ArgPhil), legal argumentation (2ndMET-ARG) and argumentation in rhetoric (1st MET-RhET); and two conferences: on computational models of argumentation (7th COMMA conference) and on argumentation and corpus linguistics (16th ArgDiaP conference). WAW hosted twelve tutorials and eight invited talks as well as welcoming over 130 participants. All the conferences and workshops publish pre- or post-proceedings in the top journals and book series in the field

Paracomplete logic Kl: natural deduction, its automation, complexity and applications

In the development of many modern software solutions where the underlying systems are complex, dynamic and heterogeneous, the significance of specification-based verification is well accepted. However, often parts of the specification may not be known. Yet reasoning based on such incomplete specifications is very desirable. Here, paracomplete logics seem to be an appropriate formal setup: opposite to Tarski’s theory of truth with its principle of bivalence, in these logics a statement and its negation may be both untrue. An immediate result is that the law of excluded middle becomes invalid. In this paper we show a way to apply an automatic proof searching procedure for the paracomplete logic Kl to reason about incomplete information systems. We provide an original account of complexity of natural deduction systems, leading us closer to the efficiency of the presented proof search algorithm. Moreover, we have turned the assumptions management into an advantage showing the applicability of the proposed technique to assume-guarantee reasoning

Inferencialismo y Relevancia: el caso de la conexividad

This paper provides an inferentialist motivation for a logic belonging in the connexive family, by borrowing elements from the bilateralist interpretation for Classical Logic without the Cut rule, proposed by David Ripley. The paper focuses on the relation between inferentialism and relevance, through the exploration of what we call relevant assertion and denial, showing that a connexive system emerges as a symptom of this interesting link. With the present attempt we hope to broaden the available interpretations for connexive logics, showing they can be rightfully motivated in terms of certain relevantist constraints imposed on assertion and denial.Este artículo proporciona una motivación inferencialista para una lógica perteneciente a la familia conexiva, tomando prestados elementos de la interpretación bilateralista de la Lógica Clásica sin la regla de Corte, propuesta por David Ripley. El artículo se centra en la relación entre inferencialismo y relevancia, a través de la exploración de lo que llamamos aserción y negación relevantes, mostrando que un sistema conexivo emerge como síntoma de este interesante vínculo. Con el presente intento, esperamos ampliar las interpretaciones disponibles para las lógicas conexivas, mostrando que pueden estar motivadas legítimamente en términos de ciertas restricciones relevantes impuestas a la aserción y la negación

On the Optimized Utilization of Smart Contracts in DLTs from the Perspective of Legal Representation and Legal Reasoning

Smart contracts are computer programs stored in blockchain which open a wide range of applications but also raise some important issues. When we convert traditional legal contracts written in natural language into smart contracts written in lines of code, problems will arise. Translation errors will exist in the process of conversion since the law in natural language is ambiguous and imprecise, full of conflicts, and the emergence of new evidence may influence the processing of reasoning. This research project has three purposes: the first aims at the resolution of these problems from logic and technical perspective to develop the accuracy and human-readability of smart contracts, by exploring a more novel and advanced logic-based language to represent legal contracts, and analyzing an extended argumentation framework with rich expressiveness; the second purpose is to investigate various existing technologies like Akoma Ntoso and Legal- RuleML, making the legal knowledge and reasoning machine-readable and be linked with the real world; third, to investigate the implementation of a mature multi-agent system incorporating the software agents with sensing, inferring, learning, decision-making and social abilities that can be fitted onto DLTs

Non normal logics: semantic analysis and proof theory

We introduce proper display calculi for basic monotonic modal logic,the conditional logic CK and a number of their axiomatic extensions. These calculi are sound, complete, conservative and enjoy cut elimination and subformula property. Our proposal applies the multi-type methodology in the design of display calculi, starting from a semantic analysis based on the translation from monotonic modal logic to normal bi-modal logic