Please solve this question.

Book : The art of Multiprocessor Programming

chapter 2 exercise 18

Exercise 18. Prove, by way of a counterexample, that the sequential time-stamp system T 3, started in a valid state (with no cycles among the labels), does not work for three threads in the concurrent case. Note that it is not a problem to have two identical labels since one can break such ties using thread IDs. The counterexample should display a state of the execution where three labels are not totally ordered.