%0 Conference Paper
%B Advances in Modal Logic, Volume 8
%D 2010
%T A Syntactic Realization Theorem for Justification Logics
%A Kai Brünnler
%A Remo Goetschi
%A Roman Kuznets
%E Lev Beklemishev
%E Valentin Goranko
%E Valentin Shehtman
%K realization theorem
%X Justification logics are refinements of modal logics where modalities are replaced by justification terms. They are connected to modal logics via so-called realization theorems. We present a syntactic proof of a single realization theorem that uniformly connects all the normal modal logics formed from the axioms $\mathsf{d}$, $\mathsf{t}$, $\mathsf{b}$, $\mathsf{4}$, and $\mathsf{5}$ with their justification counterparts. The proof employs cut-free nested sequent systems together with Fitting's realization merging technique. We further strengthen the realization theorem for $\mathsf{KB5}$ and $\mathsf{S5}$ by showing that the positive introspection operator is superfluous.
%B Advances in Modal Logic, Volume 8
%I College Publications
%P 39-58
%G eng
%U http://www.iam.unibe.ch/ltgpub/2010/bgk10.pdf