Abstract: We discuss the development of an environment for formal knowledge engineering. The Sigma system is an advance over previously developed systems in that it integrates a number of modern ontology development tools, which has motivated a number of research issues. Primary components include an ontology browsing and editing environment, a first order logic inference system and a natural l...

Argumentation is the process of supporting claims with grounds and defending them against attack. In the last decades argumentation has become an important topic in philosophy and artificial intelligence. In philosophy, the criticisms of Toulmin and Perelman of formal logic in the 1950s and 1960s gave rise to the field of informal logic, which studies informal models of reasoning and argumentat...

This paper proposes a particular kind of logics as a formal framework for the non-formal sciences. Such logics of objects turn out to be quite different from recent mathematical logic, but they can be seen as updated versions of the classic conception of logic that is due to Frege, Russell, and the early Carnap. Though obsolete, from the point of view of pure mathematics, logics of this kind ma...

Approximate logic synthesis techniques have become popular in error-resilient systems, where accuracy requirements can be traded for improved energy efficiency. Many of these operate on a circuit by substituting or removing some its portions under predefined error constraint; however, the research systematic methods to determine induced such transformations is still at an early stage. We propos...