Question 3.54

1. The order-requirement diagram accompanying Exercise 23 shows a directed edge from T₄ to T₇. Explain why this edge can be omitted from the order-requirement digraph because it is “redundant.”
2. In Exercise 23, if the direction of the edge from T₆ to T₇ were reversed, would this still be a “legal” order-requirement digraph? (Explain your answer.)