30 - 31 May 2019, Logic in London I, London, England

The workshop brings together researchers working on the logic and the philosophy of type-free notions such as functions, classes, properties, and propositions.

Due to the logical paradoxes, the traditional approach arranges such entities in hierarchies: type-theory and traditional set theory are well-known examples. The resulting picture has the obvious drawback of leaving out many legitimate objects. For instance, many innocuous circular properties and propositions cannot be assigned a place in the hierarchical approach. Similarly, it is not possible to accommodate propositions expressing quantification over all levels in a hierarchy.

The aim of the workshop is to explore and compare different approaches to type-free notions that overcome such shortcomings. It will focus in particular on the formal frameworks employed to model them, and on their philosophical motivations and applications.