test/VCM/21.xml - third_party/libxml2 - Git at Google

 <!DOCTYPE doc [
 <!ELEMENT doc (a, (b | c)*, d*)? >
 <!ELEMENT a EMPTY>
 <!ELEMENT b EMPTY>
 <!ELEMENT c EMPTY>
 <!ELEMENT d EMPTY>
 ]>
 <doc><a/><d/></doc>
	<!DOCTYPE doc [
	<!ELEMENT doc (a, (b \| c), d)? >
	<!ELEMENT a EMPTY>
	<!ELEMENT b EMPTY>
	<!ELEMENT c EMPTY>
	<!ELEMENT d EMPTY>
	]>
	<doc><a/><d/></doc>