3.1 Derivation Chain
<emma:emma version="1.0" xmlns:emma="http://www.w3.org/2003/04/emma">
<emma:interpretation id="raw">
<answer>From Boston to Denver tomorrow</answer>
</emma:interpretation>
<emma:interpretation id="better">
<emma:derived-from resource="#raw" />
<origin>Boston</origin>
<destination>Denver</destination>
<date>tomorrow</date>
</emma:interpretation>
<emma:interpretation id="best">
<emma:derived-from resource="#better" />
<origin>Boston</origin>
<destination>Denver</destination>
<date>20030315</date>
</emma:interpretation>
</emma:emma>