I have a book with denumerably many numbered pages; i.e, page 1, page 2, page 3, ... page n
On each page is written down a description of a set of positive integers
Describe a set of positive integers that cannot be described on any page of the book.
2006-06-18
18:25:10
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3 answers
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asked by
Scott R
6
in
Science & Mathematics
➔ Mathematics
ONCE YOU HAVE AN ANSWER.....!!!
Suppose your very description occurs on some page of the book-say page 10. Is 10 a member of that set or not? You will probably reach the absurdity that 10 is a member of the set only if 10 is not a member of the set. How can that be?
2006-06-18
18:39:08 ·
update #1
pages sequential for simplicity
2006-06-18
19:09:51 ·
update #2
nickipettis and Eulercrosser,
You are both correct.
Note that each can be refined to the set of all n such that n is not a member of the set on page n, not just all of them.
Using that however, can you resolve the corollary ?
2006-06-18
19:30:19 ·
update #3