Consider the Arbitrary Ttraversal algorithm of Sec 2.1 in slides, along with its assumptions and the desired correctness properties.

Each question below suggests a modification to the above algorithm.

Will the modified code work correctly? (Write YES or NO).

--In case your answer is YES, give an informal proof of correctness in less than 100 words.

--In case your answer is NO, give a counter example, pointing out, for each correctness property (safety or liveness), whether it is satisfied in this example (write YES or NO for each property).

Q1. Exactly one go() msg in transit becomes a start() msg.

Q2. Suppose initially there are TWO start() messages, in transit to the same node I.

Q3. Suppose initially there are TWO start msgs, each going to a different node (say I and A).

Q4. Initially, there is no start() msg, but there is a go() msg in transit on the line from A to B (so the sender of this message would be considered to be A by the underlying system). Assume that there are at least 3 nodes in the system.

NOTE: PLEASE ANSWER QUESTION 4, PRIORITY