Weak homomorphisms and invariants: an example

Abstract

Notions of weak isomorphism, weak epimorphism, and weak embedding are defined. For countable algebras, these specialize to the ordinary notions. Certain invariants for superatomic Boolean algebras are described. It is shown that the existence or non-existence of weak isomorphisms, weak epimorphisms, and weak embeddings between two such algebras A and B can be decided from the invariants of A and B.