About raising and handling exceptions

This paper presents a unified framework for dealing with a deduction system and a denotational semantics of exceptions. It is based on the fact that handling exceptions can be seen as a kind of generalized case distinction. This point of view on exceptions has been introduced in 2004, it is based on the notion of diagrammatic logic, which assumes some familiarity with category theory. Extensive sums of types can be used for dealing with case distinctions. The aim of this new paper is to focus on the role of a generalized extensivity property for dealing with exceptions. Moreover, the presentation of this paper makes only a restricted use of category theory.