> For more structured content this is not possible: the natural output of TeX is a sequence of graphics boxes for the glyphs, or something like a DVI format. It

> For more structured content this is not possible: the natural output of TeX is a sequence of graphics boxes for the glyphs, or something like a DVI format. It is too late to retain semantic informations, e.g. about mathematical formula. I think this applies to the natural output of TeX's "mouth" as well, i.e. one could exapnd LaTeX macros till one obtains TeX primitives, but at that point the information on structure is already lost.