\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}