code: @XmlElementDecl(namespace = "http://www.w3.org/1998/Math/MathML", name = "ln")
      public JAXBElement<ElementaryFunctionsType> createLn(ElementaryFunctionsType value) {
          return new JAXBElement<ElementaryFunctionsType>(_Ln_QNAME, ElementaryFunctionsType.class, null, value);
      }
docs: Create an instance of {@link JAXBElement }{@code <}{@link ElementaryFunctionsType }{@code >}}