// go up until first non-0 text is hit
// (innermost text is 0 in mathed)
for (int i = depth() - 1; i >= 0; --i)
if (slices_[i].text())
return slices_[i];
// go up until first non-0 text is hit
// (innermost text is 0 in mathed)
for (int i = depth() - 1; i >= 0; --i)
if (slices_[i].text())
return slices_[i];