Computing Stable Models for Nonmonotonic Existential Rules / 1031
Despoina Magka, Markus Krötzsch, Ian Horrocks
In this work, we consider function-free existential rules extended with nonmonotonic negation under a stable model semantics. We present new acyclicity and stratification conditions that identify a large class of rule sets having finite, unique stable models, and we show how the addition of constraints on the input facts can further extend this class. Checking these conditions is computationally feasible, and we provide tight complexity bounds. Finally, we demonstrate how these new methods allowed us to solve relevant reasoning problems over a real-world knowledge base from biochemistry using an off-the-shelf answer set programming engine.