texmath-0.6.7: tests/writers/munderover-01.tex
\underset{\mathrm{under}}{\overset{\mathrm{over}}{\mathrm{BASE}}}=\overset{\mathrm{over}}{\underset{\mathrm{under}}{\mathrm{BASE}}}\underset{\mathrm{under}}{\overset{\mathrm{over}}{\mathrm{BASE}}}=\overset{\mathrm{over}}{\underset{\mathrm{under}}{\mathrm{BASE}}}