On Tue, 9 Oct 2007, Shen Chen wrote:
Hi all,
The following example with the chemical module complains that "! Argument of \mtharrowfill has an extra }.".
----------- \usemodule[chemic] \starttext $$ \chemical{2H_2,PLUS,O_2,GIVES,2H_2O} $$ \stoptext -----------
The result pdf looks fine, though. The annoying problem only occurs when there's an arrow "GIVES", and only in display mode.
This error is due to a change that I suggested in math-ext (for over and under arrows). I did not check that it breaks ppchtex. Here is a fix. Add this somewhere in your style file: \def\chemicalsingleouterarrow {\dochemicalouterarrow {\hbox to \dimen2{\rightarrowfill\textstyle}}} \def\chemicaldoubleouterarrow {\dochemicalouterarrow {\lower.5\ht0\vbox {\offinterlineskip \hbox to \dimen2{\rightarrowfill\textstyle} \hbox to \dimen2{\leftarrowfill\textstyle}}}} \def\chemicaltwintipouterarrow {\dochemicalouterarrow {\hbox {\hbox to \dimen2{\rightarrowfill\textstyle}% \hskip-\dimen2 \hbox to \dimen2{\leftarrowfill\textstyle}}}} Hans, this should be corrected in ppchtex. There are a few other chemistry modules that use arrowfills, which now needs an argument specifying the math mode in which arrow should be drawn. I will look into it, but I have examples of working chemical formulas. Aditya