1 and 2

Multi setting:
Enter the first sub-polygon (the first part of the outline).

3 and 4

Plus setting:
The second sub-polygon (the second part of the outline) is added.

5 and 6

Minus setting:
This sub-polygon (projecting section) will be subtracted.

7 and 8

Minus setting:
This sub-polygon (opening, recess) will be subtracted.