paper, logics are conceived as two-sorted first-order structures, and we
argue that this broad definition encompasses a wide class of logics with
theoretical interest as well as interest from the point of view of applications.
The language, concepts and methods of model theory can thus be used to describe
the relationship between logics through morphisms of structures called transfers.
This leads to a formal framework for studying several properties of abstract
logics and their attributes such as consequence operator, syntactical structure,
and internal transformations. In particular, we treat Belief Revision Systems
(BRS) as our main example, defining the Wide Belief Revision Systems
(WBRS’s). This generalization permits to define BRS’s in an abstract setting
for classical and non-standard logics. We also show how the concept of translation
between logics can be obtained as a particular case of transfers.