I agree. Except hierarchical is problematic. The world is not hierarchical. Or, rather it is composed of innumerable hierarchies, some disjoint, some overlappi

I agree. Except hierarchical is problematic. The world is not hierarchical. Or, rather it is composed of innumerable hierarchies, some disjoint, some overlapping, some redundant, some varying with time, and which one to apply and what the levels are is a huge bikeshed / distraction Chair example: furniture/chairs/desk/chair inventory/current/reorder/chair customer/me/bought/chair customer/me/wishlist/wedding/chair products/used/modern/office/chair products/wood/four legs/padded/black/chair ad nauseum.