Null set(∅) is a subset of every set - prove it.

 Empty /Null Set is called the subset of every set,it can be proved  clearly with an example. 

• Let,A is a set: A={a,b,c,d}

             ∅={} Null set

Now, if Null Set  (∅) is not the sub-set of Set-A; then there must be an element in ∅ which does not belong to set-A But,it is true that there is not a single element in ∅. That is why ∅ is the subset of A-set.

Because,a set would not be the subset of an other set in this condition, there must be a different element in that Set.

In this way for all sets it can be proved that Null set (∅) is a subset of every set.