# Knuth algorithm problem

```I think I've just stumbled over a problem in the Knuth algorithm. Assume
the following element list:```
```
FINE   : ElementList: category=breaker, id=
FINE   : 0) aux. box w=0
FINE   : 1) aux. penalty p=INFINITE w=0
FINE   : 2) aux. glue w=5000 stretch=0 shrink=0
FINE   : 3) box w=10000
FINE   : 4) penalty p=0 w=0
FINE   : 5) aux. glue w=-5000 stretch=0 shrink=0
FINE   : 6) aux. box w=0
FINE   : 7) aux. penalty p=INFINITE w=0
FINE   : 8) aux. glue w=5000 stretch=0 shrink=0
FINE   : 9) box w=10000
FINE   : 10) penalty p=0 w=0
FINE   : 11) aux. glue w=-5000 stretch=0 shrink=0
FINE   : 12) aux. box w=0
FINE   : 13) aux. penalty p=INFINITE w=0
FINE   : 14) aux. glue w=5000 stretch=0 shrink=0
FINE   : 15) box w=10000
FINE   : 16) penalty p=0 w=0
FINE   : 17) aux. glue w=-5000 stretch=0 shrink=0
FINE   : 18) aux. box w=0
FINE   : 19) aux. penalty p=INFINITE w=0
FINE   : 20) aux. glue w=5000 stretch=0 shrink=0
FINE   : 21) box w=10000
FINE   : 22) penalty p=0 w=0
FINE   : 23) aux. glue w=-5000 stretch=0 shrink=0
FINE   : 24) aux. box w=0
FINE   : 25) aux. penalty p=INFINITE w=0
FINE   : 26) aux. glue w=5000 stretch=0 shrink=0
FINE   : 27) box w=10000
FINE   : 28) penalty p=INFINITE w=0
FINE   : 29) glue w=0 stretch=10000000 shrink=0
FINE   : 30) penalty p=-INFINITE w=0 (forced break)

Note the negative glue after each page break penalty here. Further
assume a page height of 30000 mpt. The first break point is on element
10 (difference=5000). The algorithm currently doesn't create a second
break point at element 22 because it thinks it can fit the last 3 boxes
into the 30000mpt. I believe now that the -5000mpt from the glue are not
taken into account when creating the active nodes, or rather that the
-5000 is not eliminated when calculating the difference, and therefore
the algorithm falls 5000mpt short of the target.

I'm still debuggging to see if I can locate the problem point but since
I'm still not fully at home here I thought I should make you aware of
this in case someone has a quick answer here. I'm not comfortable with