(very new to XML) Relative SystemLiteral does not seem to work

[Kiwi]

Hello.

I have a silly XML file and a silly DTD called http://foo/bar/a.xml
and http://foo/bar/a.dtd respectively. They can be validated with
http://validator.w3.org/.

a.xml is as below.
<!DOCTYPE a SYSTEM "http://foo/bar/a.dtd">
<a/>

a.dtd is as below.
<!ELEMENT a EMPTY>

But when I modified "http://foo/bar/a.dtd" to "a.dtd" and validated
them again, I was told 'Fatal Error: cannot find "a.dtd"; tried.'

I think I just used relative URI instead of absolute one where
SystemLiteral was expected. What was wrong?

Thank you.

 

[Bob Foster]

Did you upload the file? If so, it doesn't know the document base. If not,
don't know. The relative URI should be fine.

Bob Foster

 

[Logomachist]

Hello.

I have a silly XML file and a silly DTD called http://foo/bar/a.xml
and http://foo/bar/a.dtd respectively. They can be validated with
http://validator.w3.org/.

These files are at http://foo ?
There's no such thing as http://foo - if there was foo would be a top
level domain, and it's not. Unless there's some server trick here I'm
missing?

- Rob