Le Mon, Nov 14, 2005 at 06:57:09PM +0100, Joachim Schrod: > > Which of those do you want to keep? There are good arguments for all > of them. This is why, in my opinion, two tools are usefull: - a "token look ahead" - a "node look backward" The two opposites are meaningless, as far as I understand the working of TeX. The real difficulties come from having the right kind of registers for every kind of node. A workaround can be to use hbox for everything not yet implemented in registers, I don't know if it is the good solution. At least it sounds feasible easily, which is a great quality. Regards, Benjamin.