Safe Formulas in the General Theory of Stable Models (preliminary report) (2008)
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 formla of a simple syntactic form.
In International Conference on Logic Programming (ICLP) 2008.

Joohyung Lee Ph.D. Alumni joolee [at] asu edu
Vladimir Lifschitz Faculty vl [at] cs utexas edu