> Could we still define factorial? This was the problem facing the developers of the lambda calculus (which doesn’t have built-in recursion). Lambda calculus d

> Could we still define factorial? This was the problem facing the developers of the lambda calculus (which doesn’t have built-in recursion). Lambda calculus doesn't have built-in numbers either. Curiously, the standard representation of numbers in lambda calculus, the so-called Church numerals, allows for a non-recursive definition of factorial [1]: fac = λnλf.n(λfλn.n(f(λfλx.n f(f x))))(λx.f)(λx.x) > There’s more to type checking than Haskell’s rigid declarations. I don't see such rigidity since most type declarations in Haskell can be omitted as they will be correctly inferred. [1] https://flownet.com/ron/lambda-calculus.html https://flownet.com/ron/lambda-calculus.html