Hi I think the error comes from your way of using \define: you use \define\abs[1]{\lvert #1 \rvert} instead of \define[1]\abs{\lvert#1\rvert} the following works fine for me: \starttext %\define[1]\abs{|#1|} % this works \define[1]\abs{\lvert#1\rvert} % this works too $\abs{-1} = 1$ \stoptext Best regards: OK On 4 juin 2011, at 22:40, Paul Menzel wrote:
Dear ConTeXt folks,
I want to define `\abs` as the command for the absolute value. The following minimal example is also attached.
\define\abs[1]{\lvert #1 \rvert} \starttext $\lvert 2 \rvert$
$\abs{2}$ \stoptext
This does not work though.
$ context abs […] This is LuaTeX, Version beta-0.70.1-2011051923 (rev 4277) \write18 enabled. (abs.tex
ConTeXt ver: 2011.05.18 22:26 MKIV fmt: 2011.5.27 int: english/english […] ! Missing $ inserted.
system > tex > error on line 1 in file abs.tex: Missing $ inserted ...
1 >> \define\abs[1]{\lvert #1 \rvert} 2 \starttext 3 $\lvert 2 \rvert$ 4 5 $\abs{2}$ 6 \stoptext 7
<inserted text> $ <to be read again> \Udelimiter \lvert ->\Udelimiter "4 "0 "7C l.1 \define\abs[1]{\lvert #1 \rvert} ?
How should I do that correctly? I took that example from the user’s guide of the amsmath package (`texdoc amsldoc`).
Thanks,
Paul
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