Diagram Construction in Intuitionistic Logic
Shahrzad Moeiniyan Bagheri, Massoud Pourmahdian · Logic Journal of IGPL · 2006
Every classical first order structure is coded in its diagram consisting of atomic sentences it satisfies. We study diagrams for the class of constant domain Kripke models and use it to define notions of submodel, reduction, expansion and ultraproduct for a ceratin subclass of it. In particular, we study conditions under which forcing is preserved by reductions and expansions.