0
1
Added left
x
2
3
4
Added right
y
5
6
7
Changed same
8a
9
10
Changed different
12b
13
14
Deleted left
17
18
Deleted right
20
21
Left: Add+change Right: change
xx
22b
23
24
Left: change Right add+change
yy
25b
26
27
Left: Delete  Right: change
28a
29
30
Left: change  Right: delete
31a
32
33
Added same
xxx
34
35
36
Deleted same
38
39
Changed adjacent
40a
41a
42
Left: Add+change Right: change same
xxxx
43a
44
45
Left: change same Right: add+change
yyyy
46a
47
48
Left: change Right: deleted block
49
50a
51
52
53
54
55
56
57
58
59