//List-of XMLFragment
interface LoIXMLFrag {}

//List-of Attribute
interface ILoAttribute {}

interface IXMLFrag {}

//Empty list of Attributes
class MtAttribute implements ILoAttribute {
  MtAttribute() {}
}

//Non-empty list of Attributes
class ConsAttribute implements ILoAttribute {
  Attribute first;
  ILoAttribute rest;

  public ConsAttribute(Attribute first, ILoAttribute rest) {
    this.first = first;
    this.rest = rest;
  }
}

class MtIXMLFrag implements LoIXMLFrag{
  MtIXMLFrag(){}
}

class ConsIXMLFrag implements LoIXMLFrag{
  IXMLFrag first;
  LoIXMLFrag rest;

  public ConsIXMLFrag(IXMLFrag first, LoIXMLFrag rest) {
    this.first = first;
    this.rest = rest;
  }
}

class Plaintext implements IXMLFrag {
  String txt;

  Plaintext(String txtString) {
    this.txt = txtString;
  }
}

class Attribute implements IXMLFrag {
  String name;
  String value;

  public Attribute(String name, String value) {
    this.name = name;
    this.value = value;
  }
}

class Tag implements IXMLFrag {
  String name;
  ILoAttribute atts;

  public Tag(String name, ILoAttribute atts) {
    this.name = name;
    this.atts = atts;
  }

}

class Tagged implements IXMLFrag {
  Tag tag;
  LoIXMLFrag content;

  public Tagged(Tag tag, LoIXMLFrag content) {
    this.tag = tag;
    this.content = content;
  }

}