



 
Hi Raji, A relation $\mathbf{ R}$ on a set $\mathbf{ X}$ is symmetric if it is true that for each $A, B \in \mathbf{ X}$ if $A\mathbf{ R}B$ then $B\mathbf{ R}A.$ Your relation is defined by $A\mathbf{ R}B$ if and only if $A \cap B = \emptyset.$ Suppose $A$ and $B$ are sets in the domain of your relation and $A\mathbf{ R}B$ then $A \cap B = \emptyset.$ What can you say about $B \cap A?$ Penny  


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