Hans Rott (University of Regensburg)
Seminář Oddělení logiky FLÚ AV ČR
This talk explores conditionals expressing that the antecedent makes a difference for the consequent. It employs a 'relevantised' version of the Ramsey Test for conditionals in the context of the classical theory of belief revision due to Alchourrón, Gärdenfors and Makinson (1985). The idea of this test is that the antecedent is relevant to the consequent in the following sense: a conditional is accepted just in case the consequent is accepted if the belief state is revised by the antecedent, and fails to be accepted if the belief state is revised by the antecedent's negation. The connective thus defined violates almost all of the traditional principles of conditional logic, but it obeys an interesting logic of its own.
The talk also offers the logic of an alternative version, the 'Dependent Ramsey Test' according to which a conditional is accepted just in case the consequent is accepted if the belief state is revised by the antecedent, and is rejected (e.g., its negation is accepted) if the belief state is revised by the antecedent's negation.
