Giuseppe, you may or may not know about these problems already, so I decided to simply send them all. I'm using t-nath.tex 2003.12.08, updated five minutes ago from www.tug.org, ConTeXt 2004.6.26, and pdfeTeX 3.14159-1.10b-2.1 (Web2C 7.4.5). nath seems to have trouble with $$...$$-formulas. This file won't compile: \usemodule[nath] \starttext \placeformula $$a$$ \stoptext Error message: Runaway argument? \@@dollar {\to \asciiB \ExpandBothAfter \doifincsnameelse \asciiA \asciiB \ETC. ! File ended while scanning use of \convertargument. Replacing $$...$$ by \startformula...\stopformula fixes this, but the following file won't compile either: \usemodule[nath] \starttext \placeformula \startformula \sum_{i=0}^m a_i\stopformula \stoptext The culprit, it seems, is that \inlinemath uses \xdef, but \mathop@@@ puts unexpandable code into the argument of ^ and _. The following hackery seems to work: \def\mathop@@@{% \ifsp@ ^{\hbox{\edef\noexpand\!!stringa% {\noexpand\noexpand\noexpand\imath@{\the\sp@toks}}% \def\noexpand\\{,\ }\noexpand\!!stringa}} \fi \ifsb@ _{\hbox{\edef\noexpand\!!stringa% {\noexpand\noexpand\noexpand\imath@{\the\sb@toks}}% \def\noexpand\\{,\ }\noexpand\!!stringa}} \fi} Though I must confess I don't understand why the complexity with introducing \!!stringa is needed. The following version works for me: \def\mathop@@@{% \pushmacro\\ \def\\{\noexpand\text{, }}% \ifsp@ ^{\the\sp@toks}% \fi \ifsb@ _{\the\sb@toks}% \fi \popmacro\\} Parentheses in display formulas don't work: \usemodule[nath] \starttext \startformula (x) \stopformula \stoptext I don't know if at some time ConTeXt placed \the\everymath inside \everydisplay, but with the current ConTeXt, you need to \appendtoks to both. I regard the output as broken, but at least it will compile. Another bug: t-nath.tex defines \savecatcode and \restorecatcode, but these names have already been used in verb-ini.tex. I have locally replaced these with \nath!savecatcode and \nath!restorecatcode, seems to work. A math problem not related to nath: \starttext \setupformulae[align=left] \startformula \eqalignno{a&=b\cr c&=d} \stopformula \stoptext doesn't work for me. Anyone else? Regards, Christopher Creutzig PS: I won't be able to read mails in the next four weeks.