コレを用意する。% plain LuaTeX document %\mathchardef\beta="010C % in plain TeX \Umathchardef\BETA=0"0"10C {\tt\meaning\beta}\par % What is \beta? {\tt\meaning\BETA}\par % What is \BETA? $\beta$-redex, or $\BETA$-redex?\bye コレを LuaTeX 0…