texmath-0.7: tests/writers/mfrac-11.tex
\frac{A}{B + \frac{C}{D + \frac{E}{F}}} = \frac{\phantom{1} A}{B + \frac{C}{D + \frac{E}{F\phantom{1}}}}
\frac{A}{B + \frac{C}{D + \frac{E}{F}}} = \frac{\phantom{1} A}{B + \frac{C}{D + \frac{E}{F\phantom{1}}}}