Symbol of subsets

 Symbol of subsets

1) ⊂ is the Symbol of subset

For example:  A= {1,2,3}

                        B={1,2}

                        C={1}

C ⊂  A

B⊂ A

2) ⊆ is the symbol of subset or equal to.

3) Null set has only 1 subset and that is null set itself. { } ⊂ { }.