Minus times minus - a good explanation

I received a few e-mails about my question concerning minus times minus equalling plus. (Thanks). Particular thanks to Bob Lyons for the link to this explanation which worked for me. Thats that itch scratched.

When is XPath a viable application level query language?

When it is integrated with an XML DB. Check out Syncato - a very cool weblogging system by Kimbro Starken.

X# perhaps?

http://www.research.microsoft.com/~emeijer/Papers/XS.pdf [PDF]

A storage space oddity

I've just copied every digital photo I ever took onto my MP3 player's 20GB hard disk as a backup. The amount of storage space we have at our disposal these days is mind blowing. The more you contemplate the vastness of data space the more you appreciate the severe limitations of data tranmission systems. This gulf is the subject of this ITWorld article Moving a mountain with tweezers.

A compact syntax for XSD?

xscs brings some of the benefits of the Relax NG compact syntax approach to XSD. I.e. don't tie yourself up in purist knots by describing your grammar in the same syntax as the instances it describes. (A good rule of thumb, I've come to believe.).
It cannot do anything about the often heinious semantic complexity of XSD but its a help at the first-pass-grok level.

Any sufficiently monolithic technology...

is indistinguishable from spaghetti.. Brilliant! [via Tim Bray].

Minus times minus = plus? Why?

Can anyone point me to a good explanation as to why minus times minus = plus? Thanks.