Is the cow tied to the post?
Yes, the cow is tied to the post.
    src        edge_attr  dst
0     1          tied to   13
1     1      in front of    5
2     1   to the left of   15
3     1          tied to   15
4     3   to the left of   15
5     3  to the right of   12
6     3   to the left of   13
7     4   to the left of    6
8     4      in front of    5
9     5           behind    6
10    5           behind    4
11    5           behind    1
12    5           behind    7
13    6  to the right of    4
14    8        on top of    0
15    9          holding    1
16    9          wearing   11
17    9   to the left of   13
18    9  to the right of   12
19    9   to the left of   15
20    9   to the left of   14
21   10   to the left of   15
22   10   to the left of   13
23   12   to the left of    3
24   12   to the left of    9
25   13   to the left of   15
26   13  to the right of    3
27   13  to the right of    9
28   13  to the right of   10
29   13          tied to   15
30   14  to the right of    9
31   15  to the right of   13
32   15  to the right of    9
33   15  to the right of    3
34   15  to the right of   10
35   15  to the right of    1
36   16        on top of    0