ABSTRACT
When talking about solving a problem algorithmically, it is (reasonably) safe to think about a program in your favorite programming language (Python, Java, etc.). A formalization would require a formal machine model, such as RAM machines 1 , which we will try to avoid. There is danger in being too informal though: the short (Python) code fragment x = 2 for i in range(n): x = x * x print(x)
