Robert Goldblatt. Canonicity Frameworks and Ultraproducts of Polarities. In Guram Bezhanishvili, Giovanna D'Agostino, George Metcalfe, Thomas Studer, editors, Advances in Modal Logic 12, proceedings of the 12th conference on "Advances in Modal Logic," held in Bern, Switzerland, August 27-31, 2018. pages 5, College Publications, 2018. [doi]
Abstract is missing.