code: @Override
  	public QualifiedName toQualifiedName(String qualifiedNameAsString) {
  		if (criticalOperatorNames.contains(qualifiedNameAsString))
  			return QualifiedName.create(qualifiedNameAsString);
  		return super.toQualifiedName(qualifiedNameAsString);
  	}
docs: the '..' operator would be rejected by {@link org.eclipse.xtext.naming.IQualifiedNameConverter.DefaultImpl}
  so we have to enable it here.