The Fluent Calculus is presented as a comprehensive specification and programming language for endowing robots with the ability of task planning in complex environments. Based on a solution to the classical Frame Problem in pure first-order logic, our calculus allows to solve planning problems where the robot has incomplete state knowledge and which involve the use of sensors, actions with uncertain effects, actions with ramications (i.e., indirect effects), and the concurrent execution of actions. Our new theory of sensing is distinguished by its simple inference scheme for calculating the effects of actions on state knowledge and by its comparatively simple account of non-knowledge. A realization of the Fluent Calculus by means of constraint logic programming is presented. Outstanding novel features of the system are to solve the inferential Frame Problem under incomplete state information, to allow for solving planning problems with knowledge goals, and to combine nondeterminism, concurrency, and ramification.

Ontology and the concept of ontologies have attracted considerable attention in the context of research on information systems analysis and design. Being rooted in philosophy, both ontology and the concept of ontologies bear their own history of philosophical debates which have quite often been ignored when applied in the field of information systems. In this contribution it is claimed that a more comprehensive discussion of well-known philosophical issues of ontology and ontologies will help us not only to understand the scope of their applicability in the context of information systems analysis and design. It will also provide us with insights about limitations as well as with directions for issues in need of further research. The argument is critical yet affirmative. It aims at the expansion of the scope of current discourses and focuses especially on socio-philosophical aspects that need to be addressed in order to leverage the full potential of using ontology and ontologies for the provision of a theoretical foundation for information systems analysis and design..

Abstract. In this article, we study the prehistory of type theory up to 1910 and its development between Russell and Whitehead’s Principia Mathematica ([71], 1910–1912) and Church’s simply typed λ-calculus of 1940. We first argue that the concept of types has always been present in mathematics, though nobody was incorporating them explicitly as such, before the end of the 19th century. Then we proceed by describing how the logical paradoxes entered the formal systems of Frege, Cantor and Peano concentrating on Frege’s Grundgesetze der Arithmetik for which Russell applied his famous paradox 1 and this led him to introduce the first theory of types, the Ramified Type Theory (rtt). We present rtt formally using the modern notation for type theory and we discuss how Ramsey, Hilbert and Ackermann removed the orders from rtt leading to the simple theory of types stt. We present stt and Church’s own simply typed λ-calculus (λ→C 2) and we finish by comparing rtt, stt and λ→C. §1. Introduction. Nowadays, type theory has many applications and is used in many different disciplines. Even within logic and mathematics, there are many different type systems. They serve several purposes, and are formulated in various ways. But, before 1903 when Russell first introduced

More and more enterprises are currently undertaking projects to integrate their applications. They are finding that one of the more difficult tasks facing them is determining how the data from one application matches semantically with the data from the other applications. Currently there are few methodologies for undertaking this task -- most commercial projects just rely on experience and intuition.

Questo lavoro è stato condotto nell'ambito dell'attività del gruppo di ricerca