Rafael Urbaniak: Similarity and Frames

I'll talk about Bugajski's algebraic semantics for similarity relation, indicate its weak points, and provide a relational semantics which is simpler and which satisfies more of Williamson's requirements for 4-place similarity relation. Then, I discuss Bugajski's argument to the effect that interesting similarity structures can be generated by a set of properties only if those properties aren't sharp. To criticize it, I describe how non-trivial similarity structures can be generated by sets of sharp properties, if these are viewed within the framework of dynamic frame theory.