Unifiability in extensions of K4

C. Gencer, D. De Jongh
2009 Logic Journal of the IGPL  
We extend and generalize the work on unifiability of [8] . We give a semantic characterization for unifiability and non-unifiability in the extensions of K4. We apply this in particular to extensions of KD4, GL and K4.3 to obtain a syntactic characterization and give a concrete decision procedure for unifiability for those logics. For that purpose we use universal models.
doi:10.1093/jigpal/jzn032 fatcat:o4hsy6cr4jg3zahbps4qw4awmi