Mario Piazza is Full Professor of Logic and Philosophy of Mathematics at the Scuola Normale Superiore of Pisa. Previously, he has been Full Professor at University of Chieti-Pescara. He studied philosophy at the University of Rome and received his Ph.D. in Philosophy of Science from the University of Genoa in 1995. He was a post doc researcher in the Department of Mathematics at the University of Warsaw (1995-96), in the Utrecht Institute of Linguistics (OTS) (1997-98), in the Département d'Informatique at École Normale Supérieure of Paris (2000). His main results and interests are in proof-theory and its applications, computation theory, philosophy of logic and mathematics, epistemology.Gabriele Pulcini is a postdoctoral researcher at the Department of Mathematics of the New University of Lisbon. He worked as postdoctoral fellow in many academic institutions, including the Department of Computer Science at the École Normale Supérieure of Paris and the Centre for Logic, Epistemology and History of Science (State University of Campinas, Brazil). He obtained his PhD at the University of Rome 3 and the University of Aix-Marseille 2, jointly. His fields of research and interest range from the proof theory of classical and non-classical logics to the philosophy of logic, as well as the philosophy of mathematics. He is author of many research papers appeared in the most important journals in the field such as the Annals of Pure and Applied Logic and the Journal of Logic and Computation. Since 2012, he is member of the Italian Network for the Philosophy of Mathematics.