The Nature of External Axioms

Types of Axioms

• Positive ground facts, mixed ground facts, non-ground facts
• Disjunctions of facts (Horn, range restricted, general)
• Full first-order logic

Features of Axioms

• Generally, might be "dirty"
• Inconsistent
• Epistemic and assertional status
• Temporal

Storage of Axioms

• Static: SQL, SPARQL, semantic nets (WWW), RDF
• Dynamic: Executables, WWW services