Let \(M=T^2\times S^2\), and suppose \(\omega \) is a 4-form on \(M\) such that \(\int _M\omega =7\).
- Define a smooth map \(f:M\to M\) that has degree 2.
- Define a 4-form \(\theta \) on \(M\) such that \(\int _M\theta =56\), using both \(f\) and \(\omega \) nontrivially.