[texhax] Isthis a bug in LaTex?

[Petr Sojka]

On Thu, Sep 18, 2003 at 08:37:08PM +0100, Ian Collier wrote:
> Earlier I wrote:
> >I question (a) why b=10000 on that penultimate break, given that
> >\rightskip has infinite stretchability, and (b) why the break has
> >to be via @@82 rather than @@81 when on the face of it @@81 would
> >seem to give fewer demerits.
> 
> Answering my own question, I suppose (b) is because once we have hit
> b=10000 the demerits are no longer relavent.  However, (a) is still
> a mystery.

Ian,

try to uncomment the line with \adjdemerits in plain tex file below,
and read TeXbook exercise 14.11:

\hsize 360pt
%\adjdemerits=5083 %plain sets 10000 
\font\f = cmr10 scaled 1095 \f
\rightskip 0pt plus 1fil
\noindent\tracingparagraphs=1
I claim that a graph G can not have a poor subgraph with only one
or two vertices but it can have a poor subgraph
with only three vertices. If G is a graph with exactly
three vertices and it has a poor subgraph then I claim G is
complete.
\penalty-10000\penalty-10000
\par\vfill\par\penalty-20000\end

So clearly it is a tex [line breaking algortihm's] feature, not a bug, 
and has nothing to do with latex. 

Best
--ps