ABSTRACT
Interval arithmetic seems like a great idea, until you actually try to use it to solve a problem. Several examples of interval arithmetic in Part 1 wound up with an answer bound of “between –∞ and ∞,” a correct but completely useless result. The information obtained is 1∞ = 0. Unums, ubounds, and uboxes also deal with intervals, suggesting that whatever plagues interval arithmetic and has prevented its widespread adoption will also affect unum arithmetic and send would-be unum users scurrying back to the familiar turf of unknown rounding and sampling errors that produce exact-looking results.
