# Re: Checking: difference between negative stretch and positive shrink?

```Andreas L Delmelle wrote:

```
Just wondering about some KnuthSequences for spaces I noticed during a debug-session:
```
glue w=0 stretch=10008 shrink=0
penalty w=0 p=0
glue w=3336 stretch=-10008 shrink=0

```
What does it mean that the latter glue can be stretched by a negative amount?
```Why not:
glue w=3336 stretch=0 shrink=10008

Is there a difference as to how the algorithm treats these?
```
```
```
Negative stretch is not the same as a positive shrink (and vice-versa): a negative stretch is used to cancel (or diminish) a positive one provided by some other elements: for each possible break point, however, the overall stretch / shrink should always be >= 0.
```
The meaning of the mini-sequence above is:
- if there is a break at the penalty element, there is some stretch for
the line ending there
- otherwise, the overall stretch is zero

```
This is with unjustified text to give each line the same amount of stretch, so that the algorithm should build lines with similar length (while in justified text a line with many spaces and few letters could be stretched a lot).
```
HTH

Luca

```