An essay on unification and inference rules for modal logics
Vladimir Vladimirovich Rybakov, Mehmet Terziler, Çiğdem Gencer · 1999
We 1 study uniflcation of formulas in modal logics and consider logics which are equivalent w.r.t. uniflcation of formulas. A criterium is given for equivalence w.r.t. uniflcation via existence or persistent formulas. A complete syntactic description of all formulas which are non-uniflable 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 flnite basis for passive rules.