2.7 A primer in computer programming

In principle, computers can be programmed to perform or solve almost any imaginable task or problem, with the proviso that the method for resolution can be explicitly defined and the data needed for its realisation can be explicitly represented. In essence, in order to program a computer one needs to write a sequence of instructions specifying how the machine will achieve the required results. This implies that the programmer must know how to resolve the problem or task in order to instruct the machine.

In many ways, a computer program is fairly similar to a recipe for a dish: a recipe gives clear steps to prepare the dish and lists all necessary ingredients. Recipes as well as computer programs must be void of ambiguities; e.g., the statement cover and simmer for five minutes over a low heat is preferable to cover and simmer for some time . Note, however, that even though the first statement is more precise than the second, the former still implies some background knowledge to interpret it. The term low heat , for instance, may carry different meanings to a chef, to a chemist and to an astrophysicist; the chef will probably know best how to select the gas mark of the cooker. People tend to develop specific coding and languages to communicate ideas on a specific subject more efficiently. The BBC Radio 4 Shipping Forecast is a good example of an efficient coding system to communicate the weather forecast to sailors...