texmath-0.6.7: tests/writers/msubsup-05.tex
{{S}}_{{{Q}}_{4}^{3}}^{{{P}}_{2}^{1}}={{S}}_{{{Q}}_{4\phantom{\mathrm{z}}}^{3}}^{{{P}}_{2}^{1\phantom{\mathrm{z}}}}{{S}}_{{{Q}}_{4}^{3}}^{{{P}}_{2}^{1}}={{S}}_{{{Q}}_{4\phantom{\mathrm{z}}}^{3}}^{{{P}}_{2}^{1\phantom{\mathrm{z}}}}