On 05/21/2011 01:57 AM, Heiko Oberdiek wrote:

Hello,

\catcode`\{=1 \catcode`\}=2 \def\msg{\immediate\write16 }

\mathchardef\foo=-1 \msg{[\the\foo] [\meaning\foo]}

\csname @@end\endcsname\end

Result with different values:

[-1] [\mathchar"000/] [-2] [\mathchar"000.] [-3] [\mathchar"000-] [-16] [\mathchar"00/0] [-256] [\mathchar"0/00] ...

Similar behaves \omathchardef.

The documentation says, the valid ranges are \mathchardef: 0--"8000 \omathchardef: 0--"8000000

Thus it's probably a bug that negative values are accepted.

Yes, agreed. It should do: ! Bad mathchar (-1). l.5 \mathchardef\foo=-1 I'll add a tracker. Best wishes, Taco