Root Object: LOT or NOLOT Objectified Predicate Object: LOT or NOLOT Lexical Object Type Non Lexical Object Type Object + Role Abstract element for constraints Objectified Predicate SubType Mandatory Constraint Uniqueness Constraint SubSet Constraint Equality Constraint Exclusion Constraint Frequency Constraint Irreflexive Ring Constraint Intransitive Ring Constraint Acyclic Ring Constraint Assymetric Ring Constraint Antisymmetric Ring Constraint Symmetric Ring Constraint