Hello everyone,

A quick question, as I'm not sure I got it right.

Let $X=\mathbb{P}^1 \times \mathbb{P}^1$ and let $\mathcal{O}(a,b):=\pi^*_1\mathcal{O}(a)\otimes \pi^*_2\mathcal{O}(b)$. Is there a general expression for 
$$Hom_X(\mathcal{O}(a,b),\mathcal{O}(x,y))$$

Thank you