Rich’s point is the type signature actually tells you little about what the function does. You need the name, docs, tribal knowledge, your own understanding of the math… etc. to actually understand what it does. Type signature alone is a very incomplete understanding. But come on, do you think I learned how to write Haskell and don’t understand what a type signature’s value is? Give me a little credit.
Here is Rich’s work on the subject: https://youtu.be/YR5WdGrpoug?si=7C8EjQ7TVo2Ua8w7
I’m biased, but I think he’s got a point.