Reminds me of my favorite math essay: &quot;When is one thing equal to some other thing?&quot;<p>It&#x27;s a great question, much deeper and more interesting than it seems. The essay suggests thinking in terms of isomorphisms (relative to the structure you care about) rather than equality in some absolute sense, and I&#x27;ve found a fuzzy version of that to be a really useful perspective even in areas that can&#x27;t be fully formalized.<p><a href="https:&#x2F;&#x2F;people.math.osu.edu&#x2F;cogdell.1&#x2F;6112-Mazur-www.pdf" rel="nofollow">https:&#x2F;&#x2F;people.math.osu.edu&#x2F;cogdell.1&#x2F;6112-Mazur-www.pdf</a>

I think all three problems are really one problem under the hood:<p>Are these two things actually the same thing, or they separate?

I thought the two hard problems were naming things, cache invalidation, and off-by-one errors?

This is more true as stated than people want to give credit for, usually.