 Clearly, as Adams (1981: 30) notes, a “suitable restriction” on necessitation (beyond Nec*) is called for. Adams himself does not specify, but it is clear what it must be. Singular logical truths like \(\sfL\sfp \to \sfL\sfp\) are indeed true at all worlds and, hence, necessary—but only contingently so; for, by MSA, \(\Box(\sfL\sfp \to \sfL\sfp)\) is false at Prior-free worlds. More generally, just as the equivalence of necessity and impossible falsehood only holds at a world for the propositions that exist there, the necessity of a proposition at a world will only hold for the propositions that exist there. Nec* thus requires a qualification similar to \(\Box\Diamond_A\)’s: