Picard lattice of a Hirzebruch surface
= Picard lattice of a Hirzebruch surface
{c}
For the <Hirzebruch surface> $\mathbb F_n$, the <negative section of a Hirzebruch surface> $S$ and a <fiber class of a Hirzebruch surface> $F$ freely generate $\operatorname{Pic}(\mathbb F_n)$ and satisfy
$$
S^2=-n,\qquad S\cdot F=1,\qquad F^2=0.
$$