On Wed, 23 Dec 2015 16:52:22 +0100
Hans Hagen
Of course, Donald Knuth disagrees with \frac from the point of view of the aesthetics of the syntax.
Are you sure he disagrees? For instance \frac {12} {34} is less code than { {12} \over {34} } and all over the texbook (and web code) shortcuts are used. Afaik his idea of TeX is that users should do what they like best.
The issue, which has been largely discussed elsewhere, is that what Knuth had in mind is for the source code to be as readable as the formatted result in some sense. I'm sure, Hans, that you agree with this philosophy. {12 \over 34} (no inner grouping should be necessary?) reads as we (or a mathematician) would think, whereas \frac{12}{34} reads as a computer programmer might think. This last construct is simply UGLY (maybe "geeks" might disagree). A computer program should have an elegant syntax, and the syntax should not be dictated by the implementation but should be coherent with itself. This is one of the attractions of lua as a language, for it is quite elegant. Another choice of ours is MetaPost, which is quite beautiful (much, much more than pgf/TiKz that it inspired), but perhaps a bit too subtle and somewhat quirky for many users. I believe that there is a certain lore around the amsmath/LaTeX \frac{}{} that is not justified, nor should we really be promoting it. If there is indeed some penalty in handling the primitives \over, etc. in luatex, then this should eventually be fixed (but I do not believe, nor do I know, that there is, in practice). Alan