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Topic: [HM] The word "set"
Replies: 5   Last Post: Oct 2, 2004 12:31 PM

 Messages: [ Previous | Next ]
 James A Landau Posts: 217 Registered: 12/3/04
Re: [HM] The word "set"
Posted: Sep 27, 2004 9:42 AM

James Pierpont wrote a two-volume work "The Theory of Functions of a Real
Variable" which appeared in two volumes. Volume I was published in 1905 and
volume II in 1912 Both were reprinted by Dover in 1959.

Volume I page 148 section 242 "The domain of definition of a function of n
variables may be any set or aggregate of points in Rn. We with to treat now the
most elementary properties of such aggregates which we call point
aggregates." ("R" is a "German R" and means the set of all real numbers.)

For the rest of Volume I he uses the term "aggregate"---a cursory search did
not turn up another use of "set".

In volume II Pierpont uses the terms "aggregrate" and "set" interchangeably.
In some sections of volume II he prefers "aggregate" and in some sections
"set". I suspect that the chapters volume II was written or rewritten out of
sequence and that sometime between 1905 and 1912 Pierpont got into the habit of
using "set", although he did not go back and modify what he had written earlier.

Also a use of the word "class", volume II, page 318, section 289:

"Cantor has divided the ordinal numbers into classes.
"Class 1, denoted by Z1, embraces all finite ordinal numbers.
"Class 2, denoted by Z2, embraces all transfinite ordinal numbers
corresponding to well order enumerable sets; that is, to sets whose cardinal number is
Aleph-null"

- James A. Landau

Date Subject Author
9/19/04 Dean Buckner
9/26/04 John Harper
9/29/04 Udai Venedem
9/27/04 James A Landau
10/1/04 William C Waterhouse
10/2/04 Jose Ferreiros