A constructive semantics for non‐deducibility
Francesco Ciraulo · Mathematical logic quarterly · 2008
Abstract This paper provides a constructive topological semantics for non‐deducibility of a first order intuitionistic formula. Formal topology theory, in particular the recently introduced notion of a binary positivity predicate, and co‐induction are two needful tools. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)