Keyphrases
- hierarchical structures
- fixpoint
- proof theoretic
- logic programs
- deductive databases
- hierarchical structure
- horn clauses
- finite state machines
- expressive power
- model theoretic
- modal logic
- decision procedures
- inference rules
- structured documents
- sql queries
- logic programming
- datalog programs
- proof theory
- answer sets
- databases
- nonmonotonic reasoning
- query evaluation
- background knowledge
- data structure
- database systems