\begin{frame}
  \small
  
  \begin{definitions}[Properties of Elements]
  Let $\langle A, \to \rangle$ be an ARS. An element $a\in A$ is called:
  \begin{itemize}
    \item<2->
      \makebox[1.5cm][l]{\alert<2>{SN}} \alert<2>{strongly normalizing} \quad or\quad \alert<2>{terminating}\\[1ex]
      if $a$ admits no infinite rewrite sequence $a = a_1 \to a_2 \to \ldots$
      \smallskip
    \item<3->
      \makebox[1.5cm][l]{\alert<3>{WN}}\alert<3>{weakly normalizing}\\[1ex]
      if $\exists b.\; a \to^! b$
      \smallskip
    \item<4->
      \makebox[1.5cm][l]{\alert<4>{CR}} \alert<4>{confluent} \quad or\quad \alert<4>{Church Rosser}\\[1ex]
      if $\forall b,c.\; (c \FromP{*} a \to^* b \;\Rightarrow\; \exists d.\; c \to^* d \FromP{*} b)$
      \smallskip
    \item<5->
      \makebox[1.5cm][l]{\alert<5>{WCR}} \alert<4>{weakly confluent} \quad or\quad \alert<5>{weakly Church Rosser}\\[1ex]
      if $\forall b,c.\; (c \from a \to b \;\Rightarrow\; \exists d.\; c \to^* d \FromP{*} b)$
      \smallskip
  \end{itemize}
  \end{definitions}

  \onslide<6->
  \begin{block}{}
  An ARS has the property if all its elements have the respective property.
  \end{block}
\end{frame}