Revision as of 15:58, 28 January 2009 by Mkorb (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

I'm a little confused about cycle notation. I'm trying to find the permutation described by an example in the book. It says that a permutation (13)(27)(456)(8)(1237)(648)(5) can be expressed in disjoint cycle form as (1732)(48)(56). I believe the resulting permutation should be found as follows:
[1 2 3 4 5 6 7 8]
Locations 5 and 6 swap. Locations 4 and 8 swap. Location 1 becomes 7, 7 becomes 3, 3 becomes 2, 2 becomes 1.
So the resulting permutation is [7 1 2 8 6 5 3 4].
However, when I try to compute this using the original redundant form, I get something different:
[1 2 3 4 5 6 7 8]
(648): Location 4 goes to location 6. 8 to 4. 6 to 8.
[1 2 3 8 5 4 7 6]
(1237): 2 to 1. 3 to 2. 7 to 3. 1 to 7.
[2 3 7 8 5 4 1 6]
(456): 5 to 4. 6 to 5. 4 to 6.
[2 3 7 5 4 8 1 6]
(27): Swap locations 2 and 7.
[2 1 7 5 4 8 3 7]
(13): Swap locations 1 and 3.
[7 1 2 5 4 8 3 6]
This time I get a different permutation. It would appear I'm doing this all wrong. Can anyone help?

Alumni Liaison

Prof. Math. Ohio State and Associate Dean
Outstanding Alumnus Purdue Math 2008

Jeff McNeal