Positive Robinson theories and h-maximal models

Abstract

In this paper we continue the exploration of the classes of positively closed and h-maximal model of an h-inductive theory in the context of positive logic. In the section 2 we give a concrete description of the class of h-maximal models of an h-inductive theory and theirs companion theories. The section 3 is concerned to the study of the positive Robinson and locally positive Robinson theories and their connexion with the properties of the class of h-maximal models of the companion theories, and their connexion with the property of elimination of quantifiers. Before dealing with the topics mentioned above we give in section 1 a brief introduction to the positive model theory.