[throwaway7645]

Why are you citing an FP comp Sci professor? I must've missed something

[agumonkey]

seeing reduce in swift made me think about the universality of fold, which is the paper linked.

[throwaway7645]

Ah, was about to say that all goes back to lambda calculus by Church and could be found in Lisp probably around ~1958.

[agumonkey]

Actually I think there's a relation with exponentials and integral calculus. Or anything hyper-iteration related.