    <!--
                Copyright: Copyright 1998-2001 W3C (MIT, INRIA, Keio), All Rights Reserved.
    See http://www.w3.org/Consortium/Legal/.
    Author: Aaron Cohen (Intel), Jeff Boston (IBM)
               Version: May 1, 2001
                Module: Timing and Synchronization
               Feature: Interval logic and multiple begins with negative offset
             File Name: interval_logic_multiple_begins_negative_offset.smil
      Media Components: 2 QT, 1 JPG
     Expected Behavior: at t=9  video2 starts 4 seconds into the video.
                              at t=10 smile appears.
                              at t=10 video1 starts.
                            at t=15 video2 disappears.
                            at t=19 video1 disappears.
                            at t=20 smile disappears.
    -->
    <smil xmlns="http://www.w3.org/2001/SMIL20/Language">
    <body>
            <par>
                    <img id="smile" begin="10s" dur="10s"
    src="../images/smile.jpg"/>
                    <par id="par1" begin="0s;10s" dur="9s">
                            <video id="video1" begin="smile.begin" dur="10s"
    src="../videos/nasa.qt"/>
                    </par>
                    <video id="video2" begin="video1.begin-5s" dur="10s"
    src="../videos/nasa.qt"/>
            </par>
    </body>
    </smil>