Robuta

https://eprints.illc.uva.nl/id/eprint/112/ PP-2004-01: Minimal Predicates, Fixed Points, and Definability - ILLC Preprints and Publications https://www.illc.uva.nl/Research/Publications/Reports/ML/publication/3264/Algorithmic-Problems-Concerning-First-Order-Definability-of-Modal-Formulas-on-the-Class-of-All-Finite-Frames Algorithmic Problems Concerning First-Order Definability of Modal Formulas on the Class of All... https://researchportal.ip-paris.fr/fr/publications/characterizing-definability-in-decidable-fixpoint-logics/ Characterizing definability in decidable fixpoint logics - Institut Polytechnique de Paris characterizing definability decidable fixpoint logics https://www.mscand.dk/article/view/12103/10119 View of Definability and forcing in E-recursion. in e view definability forcing recursion