Re: A question Level 1 <---> level 2 mappings; arithmetic versus applications
On 6/30/2010 16:43, Michel Hack wrote:
Dan Zuras wrote:
Level 1 is the set of all possible contiguous subsets
of the extended Reals.
Based on motions 2 and 3, Level 1 only contains plain Reals, and no
infinities. It does contain unbounded intervals because those are
still "contiguous subsets of the Reals".
For what it's worth:
Oh, I guess this invalidates my previous comment on the use
of terminology "inf" and "sup": \infty is the supremum
of an interval unbounded on the right, but is not its
maximum. In any case, sorry for cluttering your mailbox
with this small irrelevancy.
Baker
Infinities are used at Level 2 to encode unboundedness.
Michel.
---Sent: 2010-06-30 21:46:49 UTC
--
---------------------------------------------------------------
R. Baker Kearfott, rbk@xxxxxxxxxxxxx (337) 482-5346 (fax)
(337) 482-5270 (work) (337) 993-1827 (home)
URL: http://interval.louisiana.edu/kearfott.html
Department of Mathematics, University of Louisiana at Lafayette
(Room 217 Maxim D. Doucet Hall, 1403 Johnston Street)
Box 4-1010, Lafayette, LA 70504-1010, USA
---------------------------------------------------------------