I wonder why people are so against building several development levels, because this is the normal way computer programming is structured otherwise: The lowest level is the assembler which expands to simple machine instructions. On top of that, one might build a language like C, which does not impose runtime checks and itself is compiled, not interpreted. Then on top of that, one might build a more advanced language with runtime checks, and often C is a language to use for writing that language. Finally this more advanced language can be used to build user applications. Similarly, in TeX the assembler might correspond to the most lowlevel macros. It would be great if one could add some kind of C compiler on top of that, which does not add much runtime overhead. The more advanced language might correspond to LaTeX itself, which is used by the user and by adding high level structures. I gather L3PL is intended to correspond to this lowest assembler level, but I think it would help if one could add a C-level, that is, if it does not add much overhead. Hans Aberg * Email: Hans Aberg <mailto:[log in to unmask]> * Home Page: <http://www.matematik.su.se/~haberg/> * AMS member listing: <http://www.ams.org/cml/>