Line	T1:		T2:
1   	Lock(R1)	Lock(R3)
2   	Lock(R2)	Lock(R1)
3   	Unlock(R2)	Unlock(R3)
4   	Lock(R3)	Lock(R2)
5   	Lock(R4)	Unlock(R2)
6   	Unlock(R1)	Unlock(R1)
7   	Unlock(R3)

Main()
Run(T1); 
Run(T2);

Example 1: Potential deadlock.