Categories über alles

I'm Professor S. MacLane
All of you must know my name
Mathematics will never be the same
Set theory has gone away
Categories rule the day
School children never weary
Of reading, writing, and category theory (x 2)
Categories über alles ...

Transformations need my will
100% natural
All hail the fully abstract
Elements are just a hack
Come quietly to the fold
Theorems with meat are boring and old
Diagrams are here to stay
Make them commute or you will pay (x 2)
Categories über alles ...

Now it is 1989
Your morphisms are all in line
But there's a knock at your office door
Functors that you can't ignore
Out of your job till you pass an exam
On the glory of the diagram
Forget the primes, remember this fact:
They're just a sequence, not even exact
Die for algebraic cohomology
So what if it's content-free
You little snot, you will crack
If you mess with Saunders Mac (x 2)
Categories über alles ...

Greg Nelson, Martín Abadi, et al