<!-- 

A DTD for Annotation Graphs (ATLAS Level 0), derived from the AIF DTD.

2000-10-26   v1.0b1  Steven Bird (LDC)
2000-11-08   v1.0b2  Steven Bird (LDC)

-->

<!-- Overview:

            AGSet  := Metadata Timeline* AG*
                   [attrs: id, version, xmlns, xmlns:xlink]

          Metadata := DCES* OtherMetadata*
     OtherMetadata := PCDATA
                   [attrs: name]

                AG := Metadata? Anchor* Annotation*
                   [attrs: id, type, timeline]

          Timeline := Metadata? Signal+
            Signal := Metadata?
                   [attrs: id, mimeClass, mimeType, encoding,
                    xlink:type, xlink:href, track?]

            Anchor := EMPTY
                   [attrs: id, type, offset?, unit?, signals?]

        Annotation := Feature*
                   [attrs: id, type, start, end]
           Feature := PCDATA
                   [attrs: name, type?]
-->

<!--
  <!ENTITY % MetadataDef SYSTEM "metadata.dtd"> %MetadataDef;
-->

<!ELEMENT AGSet
  ( Metadata, Timeline*, AG* )>
<!ATTLIST AGSet
    id          ID     #REQUIRED
    version     CDATA  #FIXED    "1.0"
    xmlns       CDATA  #FIXED    "http://www.ldc.upenn.edu/atlas/ag/"
    xmlns:xlink CDATA  #FIXED    "http://www.w3.org/1999/xlink"
    xmlns:dc    CDATA  #FIXED    "http://purl.org/DC/documents/rec-dces-19990702.htm"
>

<!ELEMENT AG
  ( Metadata?, Anchor*, Annotation* )>
<!ATTLIST AG
    id          ID         #REQUIRED
    type        NMTOKEN    #IMPLIED
    timeline    IDREF      #REQUIRED      <!-- ref to Timeline id -->
>

<!ELEMENT Timeline
  ( Metadata?, Signal+ )>
<!ATTLIST Timeline
    id          ID         #REQUIRED
>

<!ELEMENT Signal EMPTY>
<!ATTLIST Signal
    id          ID         #REQUIRED
    mimeClass   CDATA      #REQUIRED
    mimeType    CDATA      #REQUIRED
    encoding    CDATA      #REQUIRED
    unit        CDATA      #REQUIRED
    xlink:type  CDATA      #FIXED        "simple"
    xlink:href  CDATA      #REQUIRED
    track       NMTOKEN    #IMPLIED
>

<!ELEMENT Annotation ( Feature* )>
<!ATTLIST Annotation
    id         ID          #REQUIRED
    type       NMTOKEN     #REQUIRED
    start      IDREF       #REQUIRED   <!-- ref to Anchor id -->
    end        IDREF       #REQUIRED   <!-- ref to Anchor id -->
>

<!ELEMENT Feature PCDATA>
<!ATTLIST Feature
    name        NMTOKEN    #REQUIRED
    type        NMTOKEN    #IMPLIED     
>

<!--
  Note that feature content may be structured, and the recommended
  way is to use Dublin Core Structured Values DCSV (Cox & Iannella)
  http://purl.org/dc/documents/rec/dcmi-dcsv-20000728.htm
  e.g. "name.given=Eric; name.family=Van Sandt; height=170 cm"
-->

<!ELEMENT Anchor EMPTY>
<!ATTLIST Anchor
    id          ID         #REQUIRED
    offset      CDATA      #IMPLIED    <!-- anchors may have no time -->
    unit        CDATA      #REQUIRED
    signals     IDREFS     #IMPLIED    <!-- specify signals explicitly -->
>