Let G be a group. Prove that the relation R on G, defined by xRy if and only if there exists an a that belongs to G such that a^-1*x*a, is an equivalence relation.
Yes. that's exactly what I mean.
I do know what an equivalence relation is, but I got stuck at proving the reflexivity.
$\displaystyle x=a^{-1}xa $
is this trivial? Or how would I prove that?
Once I understand how to prove that, I think I'd be able to prove symmetry and transitivity.