Title: Modal Structures in Groups and Vector Spaces

Speaker: Johan van Benthem  (UvA, Stanford, Tsinghua)

Time: 15:00 ~ 17:30  (May 8th)

(Joint work with Nick Bezhanishvili.)

Abstract:  We analyze modal definability and axiomatizability of modal reasoning in commutative groups and vector spaces, showing where standard modal notions apply and where the fit is less ideal. Our positive results include several completeness theorems using techniques from hybrid logic. In the process, we also identify broader connections with complex algebras, substructural logics, and logics of (in-)dependence. The talk is based on a paper which appeared this year in the Journal of Logic and Computation, but a version which also records some later feedback from readers and listeners can be found at https://eprints.illc.uva.nl/id/eprint/1871/.