A logic of diagnosis proceeds in terms of a set of data and one or more (prioritized) sets of expectancies. In this paper we generalize the logics of diagnosis from [27] and present some alternatives. The former operate on the premises and expectancies themselves, the latter on their consequences.

In this paper Grice's requirements for assertability are imposed on the disjunction of Classical Logic. Defining material implication in terms of negation and disjunction supplemented by assertability conditions, results in the disappearance of the most important paradoxes of material implication. The resulting consequence relation displays a very strong resemblance to Schurz's conclusion-relevant consequence relation.

This paper contains different approaches to solve the problem how to construct the ultimate position out of one’s interventions in a discussion after possibly one or more position changes. In all approaches it is the aim to come as close as possible to human reasoning. Therefore all logics are adaptive logics. The first logic is an extension of an adaptive translation into S5 of the Rescher-Manor mechanisms. The second one is a dynamic proof theory based on a technique using indices. (...) In the end a satisfactory solution is given by a dynamic proof theory expressing the idea of prioritized compatibility, i.e. compatibility step by step. (shrink)

This paper is a contribution to the program of constructing formal representations of pragmatic aspects of human reasoning. We propose a formalization within the framework of Adaptive Logics of the exclusivity implicature governing the connective ‘or’.Keywords: exclusivity implicature, Adaptive Logics.