some ascii text????2#$@#$@#$ OK
balanced  <tag1><tag2>tags</tag2>brown</tag1> OK
additional <tag1><tag2>tag</tag2>without</tag1><tag3/>closing context. OK
popped off <tag1><tag2>in wrong</tag1></tag2> order.
stack non-empty <tag1>at</tag1>end<tag1>.
pop<tag1></tag1>from</tag2>empty stack.
incorrect <tag?><b>syntax</b>for tag</tag?>.
incorrect <tag/tag>syntax for tag</tag/tag>.
no match >tag
no match <tag
37&lt;38 OK
38&gt;37 OK
ampersand&amp;ampersand OK
hex number&xab99; OK
hex number&xAB99; OK
semicolon;part of ascii text OK
odd number of hex digits&x345;
ampersand without closing semicolon&gtxxx
tags that are not lowercase <Tag1>hello</Tag1>
blank line follows

multiple tags of the same name, nested: <tag1><tag1><tag1> <tag1/>hello </tag1> </tag1></tag1>