1<!DOCTYPE doc [
2<!ELEMENT doc (a?, (b, c?, d?)?, (e | f | g)*, (h+ | i | j+))>
3<!ELEMENT a EMPTY>
4<!ELEMENT b EMPTY>
5<!ELEMENT c EMPTY>
6<!ELEMENT d EMPTY>
7<!ELEMENT e EMPTY>
8<!ELEMENT f EMPTY>
9<!ELEMENT g EMPTY>
10<!ELEMENT h EMPTY>
11<!ELEMENT i EMPTY>
12<!ELEMENT j EMPTY>
13]>
14<doc>
15<i/>
16</doc>
17