Abstract
The present project aims to develop Model Theory for a family of logics that are not algebraizable by the general Blok-Pigozzi method and are simultaneously paraconsistent. But they allow semantics through Fidel structures. These semantics were first presented in the early 1970s for da Costa's logics; This work has recently been continued by Odintsov (2003), Carnielli and Coniglio (2016),…