Joshua, You said it best in the other other thread. This rule "AKHTBN if all it's blue pyramids are upright" is broken, and should be patched on the fly, either to a clear statement of the presumption or predicate: "It has blue pyramids that are all upright." ...or a removal of the presumption: "It has no blue pyramids that are other than upright." What you said, "all (none) of it's blue pyramids are upright" seems silly and presumes that null is true. "0 blue pyramids" cannot be upright. They are not "upright", or "flat", or "weird", because they are null, non-existent. Those aren't upright, because they aren't anything. They aren't. A thing that does not exist cannot meet a comparative criterion, except with nullity. David L. Willson Trainer, Engineer, Enthusiast MCT, MCSE, Linux+ tel://720.333.LANS Freeing people from the tyranny (or whatevery) of Microsoft, one at a time.