Re: [Haskell-beginners] Monad for Pair

On Wed, Nov 18, 2015 at 4:41 AM, Mike Houghton wrote: And really return x = P (x, x) doesn’t seem correct anyway.

But if you look at the type, which is essentially "a -> (a,a)" there's only one way to write it, for the same reason that there's only one "a -> a" function. Would someone please write the Monad with an explanation?

Much better if you let us know the source of this problem. Is this an exercise from some book / online course? -- Kim-Ee