- Give parameterized reductions between the following problems:
- HittingSet and SetCover in both directions.
- HittingSet to \(\mathit{WCS}[\mathcal{C}_{2,d}]\) for some \(d \in \mathbb{N}\).
- VertexCover to IndependentSet (Book problem 13.1).

- Extend the definition of \(W[t]\) to the case \(t=0\) and argue why \(W[0]=FPT\).
- Book problem 13.15.