Give an example of a set A with equivalence relations R and S for which S∘R ≠ R∘S

Somehow I've never come across relation composition before!

Anyway, this should work. Let $A = {a, b, c}$. Let $R$ equate $a, b$ and leave $c$ alone. Let $S$ equate $b, c$ and leave $a$ alone.

Then $aRSc$ but we don't have $aSRc$.

Let me know if I misunderstood the definition and I'll edit or delete my post.