\item \ifassignmentsheet \points{2}
\else \prac
\fi
\begin{enumerate}
\item
  \begin{quote}
    If I am ill, I go to the doctor. \\
    I am ill.\\
    Therefore, I go to the doctor.\\
  \end{quote}

\item
  \begin{quote}
    If I am ill, I go to the doctor. \\
    I go to the doctor.\\
    Therefore, I am ill.\\
  \end{quote}

\item
  \begin{quote}
    (Solve without using the Modus Tollens)\\
    If I am ill, I go to the doctor. \\
    I did not go to the doctor. \\
    Therefore, I am not ill.\\
  \end{quote}
\end{enumerate}