In exercise 1, a minus sign was missing. It is to show $\langle x , p \rangle \le -1$ (instead of $\langle x , p \rangle \le 1$).

The exercise sheet has been updated accordingly

In exercise 1, a minus sign was missing. It is to show $\langle x , p \rangle \le -1$ (instead of $\langle x , p \rangle \le 1$).

The exercise sheet has been updated accordingly