The conference is indeed a spoof, but in so far as what Mathematicians call a "proof" - the paper contains one. Agda is a proof assistant in the spirit of the Calculus of Constructions ( https://en.wikipedia.org/wiki/Calculus_of_constructions ).
So is the joke on Computer Scientists or Mathematicians? You decide ;)
Beware of bugs in the above code; I have only proved it correct, not tried it --Donald Knuth
Sigbovik's jokes are of the kind where the premise is completely bonkers. The rest of the development is made with the utmost rigor to highlight said bonkersitude, Reductio ad absurdum.
The wide adoption of Flask as Python's backend development framework of choice makes it quite clear that software developers have a hard time picking up April fool's jokes.
So is the joke on Computer Scientists or Mathematicians? You decide ;)
Beware of bugs in the above code; I have only proved it correct, not tried it --Donald Knuth