texmath-0.9.4: tests/writers/mfrac-07.eqn
{{a to {hphantom {roman "!"}}} over b} over {c over d} = {a over b} over {c over {d from {hphantom {roman "!"}}}}
{{a to {hphantom {roman "!"}}} over b} over {c over d} = {a over b} over {c over {d from {hphantom {roman "!"}}}}