Definition 81.18.1. In Situation 81.2.1 let $X/B$ be good. Let $\mathcal{L}$ be an invertible $\mathcal{O}_ X$-module. We define, for every integer $k$, an operation

called *intersection with the first Chern class of $\mathcal{L}$*.

Given an integral closed subspace $i : W \to X$ with $\dim _\delta (W) = k + 1$ we define

\[ c_1(\mathcal{L}) \cap [W] = i_*(c_1({i^*\mathcal{L}}) \cap [W]) \]where the right hand side is defined in Definition 81.17.1.

For a general $(k + 1)$-cycle $\alpha = \sum n_ i [W_ i]$ we set

\[ c_1(\mathcal{L}) \cap \alpha = \sum n_ i c_1(\mathcal{L}) \cap [W_ i] \]

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