Is the sky both blue and cloudless?
Yes, the sky is blue and cloudless.
   src        edge_attr  dst
0    0  to the right of    6
1    0  to the right of    2
2    2   to the left of    0
3    2   to the left of    4
4    4  to the right of    2
5    4  to the right of    6
6    6   to the left of    4
7    6   to the left of    0