Keyphrases
- query processing
- disjunctive datalog
- expressive power
- disjunctive logic programming
- datalog programs
- defeasible logic
- polynomial hierarchy
- query language
- first order logic
- default logic
- data complexity
- legal reasoning
- answer sets
- conjunctive queries
- deontic logic
- logic programming
- answer set programming
- special case
- fixpoint
- query answering
- artificial intelligence