[tel]

Well, 1930's functional programming. Those techniques developed into various type theories pretty quickly (at the time for foundational reasons, but also for comprehension/management/expressiveness reasons).

Or if you have a more strict reading, Lisp is implementation-driven FP in the 70s compared to theory-driven FP from the time.

[pjmlp]

Yes, but keeps being functional programming.

Even Haskell does not have all the mathematics theory that one could apply to functional programming.

A programming language to be representative of a programming paradigm does not need to have 100% of all ideas out there.

[tel]

I think it kind of does. FP is a moving target---more of a cultural identity than a technical definition. As it becomes more mathematically focused it will become less applicable to (some) Lisps. If this progression continues and dependently typed languages become increasingly practical we may someday call them FP-without-quotes and even displace things like Haskell and OCaml.

[pjmlp]

Except you assume there is ONE definition of what FP is, which every researcher will have a different opinion of.

[tel]

Hardly. I even begin my commentary noting that "FP is a moving target" and a social phenomenon more than a technical one. I personally avoid the term as possible in much the same way I avoid the term "data scientist". If you want me to do Data Science I'll get excited and ask you for statistical project details.