Robert O'Callahan pointed out to me some mistakes in this test that I have not yet had the time to examine or correct.
In each of the following, 1 should be the top layer and 8 the bottom layer:
8 hide me
7
6
5
4
3
2
1
1
2
3
4
5
6
7
8 hide me
1
2
3
4
5
6
7
8
1
2
4
3
6
5
7
8
6
5
4
8
7
3
2
1
1
2
3
4
5
6
7
8
4
2
7
3
5
6
1
8
Using assumed default value of z-index (may not pass):
4
2
7
3
5
6
1
8