a       0 +      0/2 +      0/2   (list is empty)
b       0 +      0/2 +      0/2   (list is empty)
-       0 +      1/2 +      0/2   | <0> | ... | <0> |
+       0 +      1/2 +      0/2   | <0> 1 | ... | <0> 1 |
-       0 +      2/2 +      0/2   | <0> 1 | ... | 0 <1> |
+       0 +      2/2 +      0/2   | <0> 1 2 ... | 0 <1> 2 |
-       0 +      3/2 +      0/2   | <0> 1 2 ... 0 1 <2> |
+       0 +      3/2 +      0/2   | <0> 1 2 ... 0 1 <2> 3 |
-       0 +      4/2 +      0/2   | <0> 1 2 ... 1 2 <3> |
+       0 +      4/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 |
-       0 +      5/2 +      0/2   | <0> 1 2 ... 2 3 <4> |
+       0 +      5/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 |
-       0 +      6/2 +      0/2   | <0> 1 2 ... 3 4 <5> |
+       0 +      6/2 +      0/2   | <0> 1 2 ... 3 4 <5> 6 |
-       0 +      7/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> |
+       0 +      7/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> 7 |
-       0 +      8/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> |
+       0 +      8/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> 8 |
-       0 +      9/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> |
+       0 +      9/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> 9 |
c       0 +     10/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 7 8 <9> |
-       0 +     10/2 +      1/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> 9 |
+       0 +     10/2 +      1/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> |
-       0 +     10/2 +      2/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> 8 |
+       0 +     10/2 +      2/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> |
-       0 +     10/2 +      3/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> 7 |
+       0 +     10/2 +      3/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> |
-       0 +     10/2 +      4/2   | <0> 1 2 ... 3 4 <5> 6 |
+       0 +     10/2 +      4/2   | <0> 1 2 ... 3 4 <5> |
-       0 +     10/2 +      5/2   | <0> 1 2 ... 2 3 <4> 5 |
+       0 +     10/2 +      5/2   | <0> 1 2 ... 2 3 <4> |
-       0 +     10/2 +      6/2   | <0> 1 2 ... 1 2 <3> 4 |
+       0 +     10/2 +      6/2   | <0> 1 2 ... 1 2 <3> |
-       0 +     10/2 +      7/2   | <0> 1 2 ... 0 1 <2> 3 |
+       0 +     10/2 +      7/2   | <0> 1 2 ... 0 1 <2> |
-       0 +     10/2 +      8/2   | <0> 1 2 ... | 0 <1> 2 |
+       0 +     10/2 +      8/2   | <0> 1 | ... | 0 <1> |
-       0 +     10/2 +      9/2   | <0> 1 | ... | <0> 1 |
+       0 +     10/2 +      9/2   | <0> | ... | <0> |
D       0 +     10/2 +     10/2   (list is empty)
d       0 +     10/2 +     10/2   (list is empty)
e       0 + ? (rolling over)
f      10 + ? (rolling over)
g      10 +      0/2 +      0/2   (list is empty)
a      10 +      0/2 +      0/2   (list is empty)
b      10 +      0/2 +      0/2   (list is empty)
-      10 +      1/2 +      0/2   | <0> | ... | <0> |
+      10 +      1/2 +      0/2   | <0> 1 | ... | <0> 1 |
-      10 +      2/2 +      0/2   | <0> 1 | ... | 0 <1> |
+      10 +      2/2 +      0/2   | <0> 1 2 ... | 0 <1> 2 |
-      10 +      3/2 +      0/2   | <0> 1 2 ... 0 1 <2> |
+      10 +      3/2 +      0/2   | <0> 1 2 ... 0 1 <2> 3 |
-      10 +      4/2 +      0/2   | <0> 1 2 ... 1 2 <3> |
+      10 +      4/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 |
-      10 +      5/2 +      0/2   | <0> 1 2 ... 2 3 <4> |
+      10 +      5/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 |
-      10 +      6/2 +      0/2   | <0> 1 2 ... 3 4 <5> |
+      10 +      6/2 +      0/2   | <0> 1 2 ... 3 4 <5> 6 |
-      10 +      7/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> |
+      10 +      7/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> 7 |
-      10 +      8/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> |
+      10 +      8/2 +      0/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> 8 |
-      10 +      9/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> |
+      10 +      9/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> 9 |
c      10 +     10/2 +      0/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 7 8 <9> |
-      10 +     10/2 +      1/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> 9 |
+      10 +     10/2 +      1/2   | <0> 1 2 ... 2 3 <4> 5 6 ... 6 7 <8> |
-      10 +     10/2 +      2/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> 8 |
+      10 +     10/2 +      2/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 5 6 <7> |
-      10 +     10/2 +      3/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> 7 |
+      10 +     10/2 +      3/2   | <0> 1 2 ... 1 2 <3> 4 5 ... 4 5 <6> |
-      10 +     10/2 +      4/2   | <0> 1 2 ... 3 4 <5> 6 |
+      10 +     10/2 +      4/2   | <0> 1 2 ... 3 4 <5> |
-      10 +     10/2 +      5/2   | <0> 1 2 ... 2 3 <4> 5 |
+      10 +     10/2 +      5/2   | <0> 1 2 ... 2 3 <4> |
-      10 +     10/2 +      6/2   | <0> 1 2 ... 1 2 <3> 4 |
+      10 +     10/2 +      6/2   | <0> 1 2 ... 1 2 <3> |
-      10 +     10/2 +      7/2   | <0> 1 2 ... 0 1 <2> 3 |
+      10 +     10/2 +      7/2   | <0> 1 2 ... 0 1 <2> |
-      10 +     10/2 +      8/2   | <0> 1 2 ... | 0 <1> 2 |
+      10 +     10/2 +      8/2   | <0> 1 | ... | 0 <1> |
-      10 +     10/2 +      9/2   | <0> 1 | ... | <0> 1 |
+      10 +     10/2 +      9/2   | <0> | ... | <0> |
D      10 +     10/2 +     10/2   (list is empty)
d      10 +     10/2 +     10/2   (list is empty)
e      10 + ? (rolling over)
f      20 + ? (rolling over)
g      20 +      0/2 +      0/2   (list is empty)

