Are elements allowed to nest within themselves?

Richard L. Goerwitz III (richard@goon.stg.brown.edu)
Wed, 9 Sep 1998 20:27:02 -0400

Just for future reference, this sort of question is easily
answered by a validator. E.g., go to

http://www.stg.brown.edu/service/xmlvalid/

and paste in a brief document like the one you posted be-
fore (with a few bits of sugar to make it taste good to
the validator):

<!DOCTYPE foo [
<!ELEMENT foo ( foo*, bar* )>
<!ATTLIST foo answer CDATA #IMPLIED>
<!ELEMENT bar (#PCDATA)>
]>

<!-- top-level "foo" element -->
<foo>
<!-- first nested "foo" element -->
<foo answer="yes">
<bar>this one</bar>
<bar>that one</bar>
</foo>
<!-- second nested "foo" element -->
<foo answer="no">
<bar>the other one</bar>
</foo>
<!-- third nested "foo" element (empty) -->
<foo/>
</foo>

Richard Goerwitz
Brown University