The complement $x^{\prime}$ of a bit string $x$ is obtained from $x$ by interchanging all 0 's and 1's. For instance, if $x=00110$, then $x^{\prime}=11001$. Suppose that we consider two switching functions $T$ and $U$ of $n$ variables the same if $T=U$ or $T(x)=U\left(x^{\prime}\right)$ for every bit string $x$. Describe all equivalence classes of switching functions under this sameness relation if $n=3$.