The documentation for 3G is not a "how to" or a tutorial on how to use the program. It is a technical reference. In that regard, it can also serve as the technical reference for earlier versions of the program. In general, to use 3G, these are implied prerequisite background knowledge that is expected of the user to use 3G effectively. Much of the material should have been covered as part of undergraduate course work. This section serves as a review of that body of knowledge.