It is a question in Principles of concurrent and Distributed programming book

(Apt and Olderog [3]) Assume that for the function f, there is some integer value i for which f (i) = 0. Here are five concurrent algorithms that search for i. An algorithm is correct if for all scenarios, both processes terminate after one of them has found the zero. For each algorithm, show that it is correct or find a scenario that is a counterexample. Table 2.11. Zero A boolean found integer in pl: found + false p2: while not found p3: iti + 1 p4: found + f(i) = integer j = 1 q1: found + false q2: while not found 93: je j - 1 94: found + f() = 0 0