case PatternLanguagePackage.PATH_EXPRESSION_ELEMENT: return createPathExpressionElement(); case PatternLanguagePackage.VALUE_REFERENCE: return createValueReference(); case PatternLanguagePackage.LITERAL_VALUE_REFERENCE: return createLiteralValueReference(); case PatternLanguagePackage.COMPUTATION_VALUE: return createComputationValue(); case PatternLanguagePackage.AGGREGATOR_EXPRESSION: return createAggregatorExpression();