[camkego]

Yeah, this is a key insight, and something I didn't learn as a software developer with many years of experience until I studied probability formally. Maybe these days this is better known. This is also known as the inclusion-exclusion principal and can be used to model failure probability.

[ethbro]

Thanks for the term! That's combinatorics, so I probably should have remembered it. :/

There are a lot of things I'd love to know the accepted name for, as I came into understanding through the backdoor. I regret that my college CS track didn't include more borrow-courses from physical engineering on reliability (and control theory). So many valuable, applicable lessons.