gistfile1.txt

For those who cannot distinguish between flat structures and tree structures.

Example 1:
Racism is bad. - Mr. A
* No it isn't. - Ms. B
* You are right. - Dr. C

is different from:

Example 2:
Racism is bad. - Mr. A
* No it isn't. - Ms. B
** You are right. - Dr. C

In Example 2, Dr. C expresses agreement with Ms. B.
In Example 1, Dr. C expresses agreement with Mr. A.

Both are tree structures, but in Example 2, the tree structure
is redundant. It's a flat structure since you CANNOT add a branch
on the tree. It's quite simple.