Are there either fences or zebras?
Yes, there is a zebra.
    src        edge_attr  dst
0     1   to the left of    7
1     1   to the left of    8
2     1   to the left of    3
3     2  to the right of    6
4     3  to the right of    1
5     3  to the right of    6
6     5       in between    4
7     6   to the left of    2
8     6   to the left of    3
9     7  to the right of    1
10    8  to the right of    1