keywords in LightRoom

Graydon oak at uniserve.com
Tue Oct 6 19:04:55 EDT 2009


On Tue, Oct 06, 2009 at 06:39:18PM -0400, Doug Franklin scripsit:
> Graydon wrote:
>> Yeah, but I got taught data structures by a graph theorist, and we did
>> graphs, acyclic graphs, directed graphs, and then acyclic directed
>> graphs, so my brain thinks the acyclic is a special case of directed,
>> rather than the other way around.
>
> That taxonomy is not acyclic. :-)

Behold the weakness of adjectives! :)

> [Directed and acyclic are orthogonal characteristics when applied to  
> graphs.  A graph may be either, neither, or both.]

Sure.  And strictly, strictly, "directed" and "acyclic" both modify
"graph", rather than each other, so the phrases are completely
equivalent, only you'd have to be a grammar robot to read it that way,
which is why a native speaker doesn't think "directed acyclic graph" and
"acyclic directed graph" sound like necessarily the same thing.

Which is how I got into this particular excavation in the first place,
and I should stop digging. :)

-- Graydon




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