[texhax] Incompatibe list can't be unboxed

Hartmut Henkel hartmut_henkel at gmx.de
Mon Aug 21 21:39:25 CEST 2006

On Mon, 21 Aug 2006, László Kálmán wrote:

> Can anyone tell me what this error message means?  I searched the web
> for an answer, but couldn't find information on it.  I get this
> message from a TeX file that I generate with a tree drawing
> preprocessor that I wrote (which uses pstricks), in the context of
> \halign{\hfil#\hfil\cr\rnode{...}{...}\cr...}.

seems you tried something along the lines (wrong):

\setbox0=\vbox{\halign{#\hfil\cr a\cr b\cr}}
\unhbox0

there is a \vbox but \unhbox is used for unboxing or vice versa. It's an
error message given by TeX. Pressing H for help gives you this nice
text:

? h
Sorry, Pandora. (You sneaky devil.)
I refuse to unbox an \hbox in vertical mode or vice versa.
And I can't open any boxes in math mode.

Regards, Hartmut