During 0-1 each task completes its initiate

During 1-2
   Task 1 completes its request (i.e. the request is granted)
   Task 2 completes its request (i.e. the request is granted)
   Task 3 completes its request (i.e. the request is granted)

During 2-3
   Task 1 releases
   Task 2's request cannot be granted
   Task 3's request cannot be granted

During 3-4
   First check blocked tasks: grant task 2's request, task 3 still blocked
   Task 1's request cannot be granted

During 4-5
   Task 2's request cannot be granted

According to the spec, task 1 is aborted now and its resources are
available next cycle (5-6).  Since task 1 had no resources, the
deadlock remains.  According to the spec task 2 is aborted as well and
its two resources become available next cycle.

During 5-6
   Check blocked tasks: Task 3's request is granted.

During 6-7
   Task 3 releases and is finished (at 7)