Are there any books on the shelf the cat is to the right of?
Yes, there is a book on the shelf.
   src        edge_attr  dst
0    1               on    2
1    1      in front of    3
2    1   to the left of    3
3    2   to the left of    3
4    3      in front of    6
5    3  to the right of    2
6    3           behind    1
7    3  to the right of    1
8    6           behind    3
9    7               on    1