That was a waste of time: 6 pages of questions, and instead of "grading" it and letting me know where I stand on FP, it says "Thanks for the gift of your time".
FYI the actual paper is https://ieeexplore.ieee.org/document/8425212 and you can get the PDF here: http://pdinda.org/Papers/ipdps18.pdf
The question is:
if a and b are numbers, it is always the case that (a + b) == (b + a)
Is a simple statement involving the commutativity over addition true for floating point? Generally, floating point arithmetic follows the same commutativity laws as real number arithmetic.
>>> a = float('inf')
>>> b = float('-inf')
>>> a + b == b + a
False> They make it clear in their notes that "are numbers" includes infinities but not NaNs.
This is definitely not very clear on the form, thought.
Another comment pointed out to the paper with the answers.
A great resource to learn about the FP corner cases is the great Random ASCII blog: