Semantics of State-Oriented Expressions in the Object Constraint Language.
Stephan Flake, Wolfgang Müller · 2003
The textual Object Constraint Language (OCL) is an official part of the Unified Modeling Language (UML). It is primarily used to formulate restrictions for UML class diagrams. Additionally, it is possible to refer to UML Statechart states in OCL expressions to reason about currently activated states.