In rule method the null set is represented by
$\{\}$
$\phi $
$\{ x:x = x\} $
$\{ x:x \ne x\} $
In each of the following, determine whether the statement is true or false. If it is true, prove it. If it is false, give an example.
If $A \subset B$ and $B \in C,$ then $A \in C$
Let $A=\{a, e, i, o, u\}$ and $B=\{a, i, u\} .$ Show that $A \cup B=A$
List all the elements of the following sers :
$C = \{ x:x$ is an integer ${\rm{; }}{x^2} \le 4\} $
Given the sets $A=\{1,3,5\}, B=\{2,4,6\}$ and $C=\{0,2,4,6,8\},$ which of the following may be considered as universal set $(s)$ for all the three sets $A$, $B$ and $C$
$\{0,1,2,3,4,5,6,7,8,9,10\}$
Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 5\, .......\, A$