Mathematica: Here, let me introduce you to the Lerch phi function!

Me: I do not wish to know that.

Mathematica: But, but … this is part of the thing you’ve been trying to calculate all week! And I finally gave it to you without crashing! And it’s harmonic!

Me: Just shoot me.

Aaagh ... Mathematica gave me this as the result of a definite integral parameterised by x and y, but when I do the same integral numerically, for specific values of those parameters, the result *doesn’t* match this expression.

Ha! The joke’s on me (though also on Mathematica).

It turns out that I can compute the same integral with a Fourier transform, and the *actual* result is just:

arctan(x/(1+y))

Take that, Lerch function!