Unification and Passive Inference Rules for Modal Logics

V. V. Rybakov, M. Terziler, C. Gencer
2000 Journal of Applied Non-Classical Logics  
We 1 study unification of formulas in modal logics and consider logics which are equivalent w.r.t. unification of formulas. A criterium is given for equivalence w.r.t. unification via existence or persistent formulas. A complete syntactic description of all formulas which are non-unifiable in wide classes of modal logics is given. Passive inference rules are considered, it is shown that in any modal logic over S4 there is a finite basis for passive rules.
doi:10.1080/11663081.2000.10511004 fatcat:thbnfkezmvacddnmjvt33hqi2e