[hiker]

> return :: x -> (a -> x)

> return x = \a -> x

>

> (>>=) :: (a -> x) -> (x -> (a -> y)) -> (a -> y)

> m >>= f = \a -> f (m a) a

>(Incidentally, these are two of the Łukasiewicz axioms for propositional calculus.)

Also the K and S in SKI combinator calculus https://en.wikipedia.org/wiki/SKI_combinator_calculus

[kmill]

The Wikipedia article mentions "The combinators K and S correspond to two well-known axioms". I wonder whether Schönfinkel and Curry had Łukasiewicz's axioms in mind when creating it? I'm finding it difficult to find the history of either the combinators or the axioms.