Thank you for reporting, we will resolve it shortly
Q.
With reference to a universal set, the inclusion of a subset in another, is relation which is
Relations and Functions - Part 2
Solution:
Let the universal set be
$U=\left\{x_{1}, x_{2}, x_{3} \ldots x_{n}\right\}$
We know every set is a subset of itself.
Therefore, inclusion of a subset is reflexive Now the elements of the set $\left\{x_{1}\right\}$ are included in the set $\left\{x_{1}, x_{2}\right\}$ but converse is not true i.e.,
$\left\{x_{1}\right\} \subset\left\{x_{1}, x_{2}\right\} \text { but }\left\{x_{1}, x_{2}\right\} \not \subset\left\{x_{1}\right\}$
Hence, the inclusion of a subset is not symmetric.
Thus, the inclusion of a subset is not an equivalence relation.