Solving Symmetric Group Induction Proof: Hints for Double Induction

  • Thread starter Thread starter Bashyboy
  • Start date Start date
  • Tags Tags
    Induction Proof
Bashyboy
Messages
1,419
Reaction score
5

Homework Statement


Consider the symmetric group ##S_n##. I am trying to establish that ##(i,i+1)=(1,2,...,n)(i-1,i)(1,2,...,n)^{-1}##

Homework Equations

The Attempt at a Solution



I am trying to decide whether I need double induction or not. I have done several calculations to see whether I can get away with one induction, but it isn't clear to me whether this is possible. I could use some hints.
 
Why don't you simply apply the mappings for the cases ##j< i-2\, , \,j > i-1## and ##j \in \{i-2,i-1\}## if read from left to right? It is no recursive definition but an explicit formula, so why use induction?
 
Hold on! I forgot that I proved that ##\sigma (x_1,x_2,...,x_n) \sigma^{-1} = (\sigma(x_1),...,\sigma(x_n))##, which makes the problem trivial.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K