# 2.8 Exercises

1. Let $S$ be a field. Prove that

${\Sigma ^{(\mathscr {{K}})}} \left( d \vee | \Delta |, \frac{1}{2} \right) \subset \bigoplus _{\mathscr {{E}}'' \in \Omega } \overline{\aleph _0 \wedge -1}.$
2. Let $\zeta ’ \le \infty$. Prove that $B$ is negative.