s $$\begin{gathered} {  \begingroup   \begingroup\lccode`~=`,     \lowercase{\endgroup\def~}{\pFcomma\mkern\pFqskip}  \mathcode`,=\string"0000   {}_{0}F_{0}\biggl(\genfrac..{0pt}{}{0/0,0/0}{0/0};\frac{00}{00}\biggr)  \endgroup }=\frac{0}{0