Example

There is no greatest integer \(k\) because

\[\begin{equation*}
  \forall k \in \mathbb{Z}
  \quad
  \exists \ell \in \mathbb{Z}
  \quad
  (\ell > k),
\end{equation*}
\]

that is

for every integer \(k\), 

there exists some integer \(\ell\) 

greater than \(k\),

such as \(\ell = k + 1\).