J. J. Lee

Safe first-order formulas generalize the concept of a safe rule, which plays an important role in the design of answer set solvers. We show that any safe sentence is equivalent, in a certain sense, to the result of its grounding—to the variable-free sentence obtained from it by replacing all quantifiers with multiple conjunctions and disjunctions. It follows that a safe sentence and the result of its grounding have the same stable models, and that stable models of a safe sentence can be characterized by a formula of a simple syntactic form.

D. Lewis proposed the reformed conditional analysis of disposition to handle Martin's influential counterexamples to the simple counterfactual analysis. Some philosophers, however, argue that the mere fact that the reformed conditional analysis of disposition can handle Martin's counterexamples should not be regarded as a reason to prefer the reformed conditional analysis to the simple analysis. In this paper, I argue that the reformed version should be preferred not because it can handle Martin's counterexamples but because there are other counterexamples to the simple conditional analysis