What is the minimum makes pan on Machine A in the Exercise?

What jobs play a role in deriving the minimum? Trace the algorithm that computes J and J to verify this.

Exercise :

Suppose that in the problem of Table,  Jobs 2, 3, and 4 are assigned to Machine A.

Use the edge-finding rules to find jobs that must precede, or follow, subsets of jobs, and update the bounds accordingly.

Note that when bounds have been updated, it may be possible to find additional edges.

For example, initially one cannot deduce that Job 3 must follow 2 (so that E3 is not updated), even though one can deduce that Job 2 must precede {3, 4} (which updates L1).

However, after L1 is updated, one can deduce that 3 follows 2 and update E3. In this case, edge finding identifies all possible bound updates, but this is not true in general.