# File proofreader.rb, line 95
    def datatype?(elora, die=nil)
      die = @proofsheet.die(elora.inherited_namespace, elora.absolute_xpath) if not die
      validity = true  # default cdata, so valid
      if die
        if die.datatype
          dts = Datatypes.new
          if not dts.valid?(die.datatype, content(elora))
            validity = false
            error = "DATATYPE '#{content(elora)}' :#{die.datatype}:"
            @errors << [die.namespace, die.xpath, error]
          end
        end
      end
      return validity
    end