The paper studies the phenomenon of signalling in logics for imperfect information, such as Hintikka’s IF logic. It is shown that signalling is a phenomenon that at the one hand is essential for the semantics, but at the other hand is a source of tricky phenomena. Several properties which in the literature are claimed to hold for such logics, turn out to fail due to signalling: IF logic is not a conservative extension of predicate logic, renaming of variables is not always allowed, the prenex normal form theorem does not hold, and slashed connectives cannot easily be eliminated.
|Title of host publication||The Age of Alternative Logics : Assessing the Philosophy of Logic and Mathematics Today|
|Editors||J.F.A.K. Benthem, van, G. Heinzmann, M. Rebuschi, H. Visser|
|Place of Publication||Dordrecht|
|Publication status||Published - 2006|
|Name||Logic, Epistemology, and the Unity of Science|