In her 1993 book Before the Digital: Why We Shouldn’t Depend on Software, Ruth Wiener stated, “Even a medium-sized software system is one of the most complex products ever created by human beings, and the software development process is one of our most intricate activities. Regardless of the resources—labor, capital, or time—we invest, the outcome is often only basic reliability, and even after the most thorough and rigorous testing, errors will inevitably persist. We can never test all potential inputs or exhaustively verify all executable paths within a system.”