This thesis provides a few results regarding the natural dualisability of certain {0, 1}-valued unary algebras with zero. We use pp-formulae to develop a sufficient criterion for non-dualisability of such algebras. With this criterion, we show that {0, 1}-valued unary algebras with zero with unique rows whose rows form an order ideal (with respect to the lattice order {0, 1}ⁿ under 0 < 1) are not dualisable if its rows do not form an lattice order. For the case where the rows do form a lattice, we use the Interpolation Condition to show that the algebra is dualisable. The last result of this thesis provides another sufficient criterion for non-dualisability by looking at two-term reducts. --Leaf ii.
