Naming, but not in the way you think. Our knowledge represents a minute portion of reality. Names are the visible portion of that knowledge. Phil Karlton once said, “there are only two hard things in Computer Science: cache invalidation and naming things.” One is a real problem; the other is a problem of defining reality. A misbehaving cache algorithm compromises the system’s integrity. Inadequate names can compromise the system’s entire existence. On the surface, this...