The Y combinator followed from of the invention of λ-calculus whereas formal logic predated both Russell as well as Curry/Haskell by a large margin. Also, the i

The Y combinator followed from of the invention of λ-calculus whereas formal logic predated both Russell as well as Curry/Haskell by a large margin. Also, the idea of a "fixed point" (consider x^2-3x+4 where there's a fixed point at x=2) had already been recognized.