Chapter 3.2, Problem 6E

In Example 3 of section 3.1, find elements $a,b,$

and $c$ of $S(A)$

such that $ab=bc$

but $a\ne c$.

From Example 3 of section 3.1: $A=\{1,2,3\}$ and $S(A)$

is a set of bijective functions defined on $A$.