Maybe by adding in headers LaTex Header in the style of a org file it
could work

$\begin{prooftree} \AxiomC{$A$} \AxiomC{$A \to \bot$} \RightLabel{\scriptsize{$\to E$}} \BinaryInfC{$\bot$} \end{prooftree}$

it works !!!

Thanks a lot Bastien, you are a genius !

Best wishes,

Jo.