There are different order relationships. The inclusion relationship between two sets is an order. So we can say that R<S ⇔ R⊂S.
Therefore it is easy to distinguish, and order, the two sets given in this set:
{a}<{a,b}={b,a} ⇔ {a}⊂{a,b} which is true.
We can define L(X) as e where {e}=y...