Every engineering field is founded on a body of fundamental scientific and mathematical principles providing a basis for the design process and enabling designers to systematically validate the major characteristics of a proposed system. In recent years, computing science has generated a similar body of principles allowing software engineers to design error-free programs. This book presents this core of knowledge. The concepts covered are based on the view that a variable is a triple of a name, a set, and an element of that set (a value); that a data environment (the execution) of a program is a sequence of variables; and that a statement, subprogram, or program serves to map a data environment into another data environment. While the material is treated in a mathematically rigorous fashion, it is carefully written to show software developers how to apply theory to practical design tasks.
