Is the dog sleeping on a bed?
No, the dog is sleeping on the couch.
   src        edge_attr  dst
0    0   to the left of    5
1    0   to the left of    2
2    0   to the left of    6
3    2  to the right of    0
4    5  to the right of    0
5    6  to the right of    0
6    7      sleeping on    1