\begin{frame}{Russell's Barber Paradox} \paradox \pause\medskip What does the law require of the barber?\pause{} \uncover<12->{\alert{He has no option!}} \medskip \begin{description} \item[Case 1: The barber shaves himself.]\mbox{}\pause % Then he does \mediumblue{\eqref{self-shaved}} and \mediumblue{\eqref{barber-shaved}}. \pause By doing \alert{both \eqref{self-shaved} and \eqref{barber-shaved}}, he violates the law that only permits exactly one of these options. \pause $\;\;\alert{\xmark}$ \pause\smallskip \item[Case 2: The barber does not shave himself.]\mbox{}\pause % Then he does not do \mediumblue{\eqref{self-shaved}}. \pause As he is the barber, he also is not shaved by the barber. So he does not do \mediumblue{\eqref{barber-shaved}}. \pause By doing \alert{neither \eqref{self-shaved} nor \eqref{barber-shaved}}, the law is again violated. \pause $\;\;\alert{\xmark}$ \end{description} \vspace{10cm} \end{frame}