Implicative Filters Research Articles

Some operations on lattice implication algebras

We introduce the concept of a ⊗‐closed set and a ⊗‐homomorphism in lattice implication algebras, and we discuss some of their properties. Next, we introduce the fuzzy implicative filter and obtain equivalent conditions. Finally, we discuss the operation ⊗, fuzzy filters and fuzzy implicative filters.

On n‐fold implicative filters of lattice implication algebras

We introduce the notion of n‐fold implicative filters and n‐fold implicative lattice implication algebras. We give characterizations of n‐fold implicative filters and n‐fold implicative lattice implication algebras. Finally, we construct an extension property for n‐fold implicative filter.

Fantastic filters of lattice implication algebras

The notion of a fantastic filter in a lattice implication algebra is introduced, and the relations among filter, positive implicative filter, and fantastic filter are given. We investigate an equivalent condition for a filter to be fantastic, and state an extension property for fantastic filter.

On Special Implicative Filters

In her well-known book, Rasiowa states without proof that in implicative algebras there is a one-to-one correspondence between kernels of epimorphisms and the so-called special implicative filters, and that in the logic whose algebraic counterpart is the class of implicative algebras the deductive filters coincide with the special implicative filters. We show that neither claim is true, and how to repair the situation by redefining some of the notions involved. We answer other questions concerning special implicative filters, taking the theory of algebraizable logics of Blok and Pigozzi as a framework to approach the question in a systematic way.