Search for parentage throughout the hierarchy

[srdiamond]

UR should try to emulate part of Idea!'s ability to do Boolean searches based on category membership. Although it probably isn't consistent with UR's less structured design to have a mechanism automatically to enter such searches, it should be possible to accomplish the same with slightly less ease by entering categories from the tree and asking UR to find all the subordinates and various Bolean combinations thereto.

So if you have a hierarchy like

I Animal
A. Mammal
1 Primate

It should be possible to input "Animal," ask for all Children, to find all items falling under Mammal, including "Primate" and its subordinates.

Boolean combinations of these sets can be formed in the usual way.

At present UR doesn't detect words in headings, so it isn't possible to see how this feature is intended to work when it is changed.