Graph Nodes:
X1;X3;X4;X5;X7;X8;X9;X10;X12;X13

Graph Edges:
1. X1 o-> X13
2. X1 o-> X7
3. X1 o-> X8
4. X10 <-> X12
5. X3 o-o X1
6. X3 o-> X12
7. X3 o-> X13
8. X4 o-o X3
9. X4 o-> X7
10. X5 o-> X8
11. X7 --> X10
12. X7 <-> X13
13. X7 <-> X8
14. X8 --> X12
15. X8 <-> X13
16. X9 o-> X10
17. X9 o-> X12

