Hello, as I might have mentioned before, I'm working on a ConTeXt module that would give part of the functionality available in the LaTeX package Nath; as I'm not really an expert in either of the topics involved, I'm going at it slowly, starting with the simple things; the first thing I implemented was a natural way to write extensible arrows. It came up pretty fine and works quite good, but there seems to be a sizing problem. First of all, please find attached t-nath.tex (the module) and nathtest.tex (a test file). As you may notice if you compile the nathtest document, sub and superscripts to the single-line arrows are much to high or low; browsing about I noticed that in AMS-LaTeX the minus that extends the single-line arrows is "smashed", to prevent this problem; I did try to smash it (replacing \mathop- with \mathop{\smash-}), but it didn't seem to help. What do the experts here think? -- Giuseppe "Oblomov" Bilotta