There could only be one good choice for which of my letter-F essays to feature today. I got a request, I think from Vayuputrii, to explain the Fredholm Alternative for this year’s A-to-Z. I had an essay about exactly that for the End 2016 A-to-Z, and didn’t think I could improve it enough to justify rewriting. It’s an idea which comes from Functional Analysis, where mathematicians get really hard-core about doing to functions the stuff we otherwise do to numbers.
Happy to say, all of the End 2016 A-to-Z essays are gathered at this link. And I hope to continue this year’s sequence on Tuesday.