Relation-changing modal operators: Fig. 1.

Undecidability of Relation-Changing Modal Logics

Relation-changing modal logics are extensions of the basic modal logic that allow to change the accessibility relation of a model during the evaluation of a formula. In particular, they are equipped with dynamic modalities that are able to delete, add and swap edges in the model, both locally and globally. We investigate the satisfiability problem of these logics. We define satisfiability-prese...

Fig. 1

Bilattices and Modal Operators

A bilattice is a set equipped with two partial orders and a negation operation that inverts one of them while leaving the other unchanged; it has been suggested that the truth values used by inference systems should be chosen from such a structure instead of the two-point set {t, f}. Given such a choice, we redefine a modal operator to be a function on the bilattice selected, and show that this...

Modal Operators for Coequations

We present the dual to Birkhoff’s variety theorem in terms of predicates over the carrier of a cofree coalgebra (i.e., in terms of “coequations”). We then discuss the dual to Birkhoff’s completeness theorem, showing how closure under deductive rules dualizes to yield two modal operators acting on coequations. We discuss the properties of these operators and show, given a familiar condition on t...

Cross-Modal Effects on Perception 1 Seeing Sound: Changing Visual Perception Through Cross-Modal Interaction

A single flash of light accompanied by a series of beeps gives the impression of flickering (Shams, Kamitani, & Shimojo, 2000). Thus, an unambiguous visual stimulus appears different when paired with an auditory stimulus. Similarly, with a flashing pattern, we find that beeps can increase or decrease perceived number of flashes. Furthermore, the perceived number or flashes can either improve or...