texmath-0.6.7: tests/writers/mfracZcomp-21.tex
\mathrm{Inline\ double\ up\ down\ arrows,\ text\ style,\ thick\ line~}\Updownarrow \frac{{sin}{\theta }}{{M}} \Updownarrow \mathrm{~the\ end.}\mathrm{Inline\ double\ up\ down\ arrows,\ text\ style,\ thick\ line~}\Updownarrow \frac{{sin}{\theta }}{{M}} \Updownarrow \mathrm{~the\ end.}