Is there any cow or zebra that is not small?
No, there is a cow but it is small.
   src        edge_attr  dst
0    1  to the right of    3
1    1   to the left of    5
2    3   to the left of    1
3    5  to the right of    6
4    5  to the right of    1
5    6   to the left of    5