$\mathcal{O}_X$ 的一阶上同调。\(a +b\) \(a + b = c\) $$\begin{aligned} a x + by =c\end{aligned}$$ \(a\) \[ax+ by =c \] $$\begin{align}ax+ by &=c \\ y &=c\end{align}$$ $$a =b $$ $$a=c =d$$
$\mathcal{O}_X$ 的一阶上同调