Hint on Dicscussion 4.4: Recall the first example we saw of a structure, in class: pt.x = 3; pt.name = 'Homestar'; Now do the same thing for a time interval structure -- no need to create an array of structures; just show how you'd create a single structure representing some time span, like the lifetime of some famous person. I'm looking for a two-line answer like the one above. So, you should ask yourself two questions: (1) how can I efficiently represent the difference between BC and AD, and (2) what famous person should I choose as an example? For (1), think about how you might compute a person's lifespan based on their birth and death years, using simple arithmetic (hint: how do you know how old YOU are right now?). For (2), a good choice would be someone who lived around the year 0, like a Roman emperor.