Jobco Shop has 10 outstanding jobs to be processed on a single machine. The following table provides processing times and due dates. All times are in days, and due time is measured from time 0:

Job Processing time (day) Due time (day)

1 10 20 2 3 98 3 13 100 4 15 34 5 9 50 6 22 44 7 17 32 8 30 60 9 12 80 10 16 150 If job 4 precedes job 3, then job 9 must precede job 7. The objective is to process all 10 jobs in the shortest possible time. Formulate the model as an ILP, and determine the optimum solution by modifying the AMPL file amplEx9.1-4.txt.