Chapter 6.1, Problem 2CQ

To determine

(a)

To explain:

The meaning of two sets $A$ and $B$ in $A\cup B\subseteq A$.

To determine

(b)

To explain:

The meaning of two sets $A$ and $B$ in $A\cup B=\varphi$.

To determine

(c)

To explain:

The meaning of two sets $A$ and $B$ in $A\cap B=B$.

To determine

(d)

To explain:

The meaning of two sets $A$ and $B$ in $A\cap B=\varphi$.