texmath-0.6.7: tests/writers/munder-09.tex
\overset{\phantom{\mathrm{fail}}}{\underset{\mathrm{bottom}}{\mathrm{-\ middle\ -}}}=\underset{\mathrm{bottom}}{\overset{\phantom{\mathrm{fail}}}{\mathrm{-\ middle\ -}}}\overset{\phantom{\mathrm{fail}}}{\underset{\mathrm{bottom}}{\mathrm{-\ middle\ -}}}=\underset{\mathrm{bottom}}{\overset{\phantom{\mathrm{fail}}}{\mathrm{-\ middle\ -}}}