20.49.2.1
$$\label{cohomology-equation-projection-formula-map} Rf_*E \otimes ^\mathbf {L}_{\mathcal{O}_ Y} K \longrightarrow Rf_*(E \otimes ^\mathbf {L}_{\mathcal{O}_ X} Lf^*K)$$

In your comment you can use Markdown and LaTeX style mathematics (enclose it like $\pi$). A preview option is available if you wish to see how it works out (just click on the eye in the toolbar).