Dear list members,

Why the following code gives me the following error?

Code:

\begingroup \catcode`\"=12
    \gdef\newmcodes@{\mathcode`\'39\mathcode`\*42\mathcode`\."613A%
    \ifnum\mathcode`\-=45 \else
        \mathchardef\std@minus\mathcode`\-\relax
    \fi
    \mathcode`\-45\mathcode`\/47\mathcode`\:"603A\relax}
\endgroup
\definemathcommand[xyz][nolop]{\newmcodes@
\kern\zeropoint\mfunction{fancy-function-name'*.:}}
\starttext
$\xyz$
\stoptext

Error:

tex error       > error on line 13 in file /Users/maggyero/Desktop/test.tex: ! Extended mathchar used as mathchar (4203026)
<to be read again> 
=
\newmcodes ...thcode `\."613A\ifnum \mathcode `\-=
                                                  45 \else \mathchardef \std...
<argument> \newmcodes @
             \kern \zeropoint \mfunction {fancy-function-name'*.:}
\486>nolop #1->\mathop {#1
                          }\nolimits 
l.13 $\xyz
        $

Thank you in advance.


Maggyero