Steve Bennett wrote:
On 8/22/06, Charlie Reams calr3@cam.ac.uk wrote:
Can someone point me to one of these cycles? I don't remember seeing one, although I've no doubt they exist. I just can't imagine a situation in which much is gained by allowing it and, given that certain features would be a lot easier if the system were guaranteed cycle-free, I think we might be better off disallowing them. But I'd like to see a few of them "in the wild" before making my mind up.
They're obviously not easy to find since we have no built in features to do that, and every time one becomes known, it gets fixed :) Maybe Magnus's tool can help us out? I don't think we have any permanent, accepted ones, if that's what you're asking...they just happen from time to time when enough sufficiently dubious category links get made...
Steve
The problem is different senses of 'subcategory': there's [1] "the set of objects in B are a strict subset of the set of objects in A", which is loop-proof, and [2] 'B is a topic that is usually discussed in the context of A'
For example:
London -[2]-> Thames Valley -[1]-> London, comes to mind
Russia -[2]-> Soviet Union -[1]-> Russia, as well.
Also, another entirely reasonable cycle would be:
Universe -[contains]-> Human beings -[who have]-> Human thought -[which includes]-> Philosophy -[which studies the]-> Universe
See [[WordNet]] for a serious attempt to tease out the relationships between concepts in detail: there are _lots_ of possible ways that one thing can be related to another.
-- Neil