Now, I've got a background as database admin and I thought IS NOT was pretty simple. Sure, it was a long time ago but statement like WHERE COLUMN IS NOT NULL are fairly simple and easy to understand.
Then I checked out
the patent - all 15 screen pages of it (at 1024x768). OMFG, is really that hard?!? I guess Patent Writer is one more career I won't be considering any time soon!
UPDATE: It's been pointed out that this refers to BASIC not SQL (I didn't actually read the patent!) It still doesn't change the fact that "If a IsNot b Then ..." is not eactly difficult to understand!