Two of the chains (C and D) have been omitted to speed the demo, so one A and
one B are present. The first display is the TOC. Interesting nodes to
'click' on (use the rightmost icon) are:
The BIBliography (click on the icon of the XLIST container);
The S-E-Q (sequence). The chain sequences are correct but there is
a bug which plots the features on both chains