I found a detailed paper which outlines the rules of interval arithmetic for closed intervals, including unbounded closed intervals, but it makes no mention whatsoever about open intervals.
I'm hoping to write a package of software which handles interval arithmetic, and I'd like to include open intervals and mixed-type (left-open, right-open) intervals if possible.
Is someone able to tell me whether arithmetic is defined for open and mixed intervals, and point me to the rules which govern such arithmetic if so?
Unums are a number format that supports open intervals and (some) exact numbers. In particular, it supports a number that is greater than zero and less than the smallest exact number.