UNCOUNTABLY MANY DUALISABLE ALGEBRAS
Jane G. Pitkethly · International Journal of Algebra and Computation · 2011
Fix a finite set M with at least three elements. We find uncountably many different clones on M, each of which is the clone of term functions of a strongly dualisable algebra. This provides a solution to the Finite Type Problem of natural duality theory: there are finite algebras that are dualisable but not via a structure of finite type.