A program inputs information, processes it, and outputs the results. This chapter shows how a C++ program inputs, processes, and outputs values. It reviews programming at Level HOL6 and assumes that you have experience writing programs in some high-order language—not necessarily C++—such as C, Java, or Ada. Because this book presents concepts that are common to all those languages, you should be able to follow the discussion despite any differences in the language with which you are familiar.
A computer can directly execute statements in machine language only at Level ISA3, the instruction set architecture level. So a Level HOL6 statement must first be translated to Level ISA3 before executing. Figure 2.1 shows the ...