for every formula "B". Note that σ is a mgu of "A". In transitive modal and superintuitionistic logics with the finite model property (fmp), one can characterize projective formulas semantically as those whose set of finite "L"-models has the extension property: if "M" is a finite Kripke "L"-model with a root "r" whose cluster is a singleton, and the formula "A" holds in all points of "M" except for "r", then we can change the valuation of variables in "r" so as to make "A" true in "r" as well. Moreover, the proof provides an explicit construction of a mgu for a given projective formula "A".