Zachriel
Posts: 2723
Joined: Sep. 2006
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| Quote (olegt @ April 04 2009,10:43) | Joe has no one to talk to on his own blog, so he goes to UD to say this: | Quote | | I understand perfectly well what nested hierarchy means. |
Bwahahaha! |
That brings back fond memories of Sam of Ballyvourney and the stuff in his pocket. Joseph had a great deal of trouble realizing that we could treat the contents of Sam's pocket as a set—even if his pocket were empty (which with Sam is often the case).
| Quote | Zachriel: Are these sets?
* Sam's male descendents.
* Twigs on a single branch.
* My bushel of apples.
* The contents of Sam's pocket.
* What if my pocket is empty?
Let's call the contents of a pocket, pocket-stuff. Now, Sam is from Ballyvourney.
* Is the set 'Sam's pocket-stuff' nested within the set of 'Ballyvourney pocket-stuff'?
* And as Ballyvourney is in County Cork, is the set 'Ballyvourney pocket-stuff' nested within the set 'County Cork pocket-stuff'?
* And is the set 'County Cork pocket-stuff' nested within the set 'Irish pocket-stuff'?
Joseph: Only if Sam is in Ballyvourney.
Zachriel: You must not know Sam. Sam can always be found at the Ballyvourney Mills Inn dancing the Ballyvourney Jig. |
Heh. Anyway, this was meant to just be a quick prelude to a discussion of nested hierarchies in terms of sets. But then...
| Quote | Joseph: The empty set is not a subset of itself.
Zachriel: The empty set is a subset of every set, including itself. Every set is a subset of itself. And every set is a subset of the union of that set with any other set. Hence,
'Sam of Ballyvourney's pocket-stuff' is a subset of 'Ballyvourney pocket-stuff'. |
Even after weeks, Joseph refused to learn anything whatsoever. His adamantine ignorance is astounding.
Finally, Joseph said I couldn't post unless I supported a strawman of his devising. That was back during Davescot's bout with coulrophobia. Good times.
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You never step on the same tard twice—for it's not the same tard and you're not the same person.
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