David thanks for the fast and concrete answer, which schema validator do you sugest to use with XML Spy?

>I am trying to import MathML Schema in XMLSpy 2004 release 2. > I can do it because I get the message >I just tried it and it is complaining about the empty in >mathml2/common/common-attribs.xsd >deleting that line makes xmlspy happy (and I'm not sure what the >intent of that line was, I'd need to check with the schema spec, >or the author of the schema, Stephane?) >Other schema validators I've used have not objected to this >David >-- >http://www.dcarlisle.demon.co.uk/matthew >________________________________________________________________________ >This e-mail has been scanned for all viruses by Star Internet. The >service is powered by MessageLabs. For more information on a proactive >anti-virus service working around the c lock, around the globe, visit: >http://www.star.net.uk >________________________________________________________________________