parserImport XOCL; import Associations; context Associations @Class Multiplicity isabstract // The multiplicity of attribute en-ds is represented as an instance // of a concrete sub-class of this class. Ends may have multiplicity // 1, 0-1, * or a range n to m. The multiplicity of both en-ds defines // the invariant constraint that holds between the classes and the // attributes corresponding to the en-ds. @AbstractOp typeExp(type):Performable // Association en-d types are specified without collection constructors. // This operation wraps a collection type constructor if required. end @AbstractOp labelString():String // All subclasses of multiplicity must define how they are displayed // (e.g. on a diagram) end end