Re: [Haskell-cafe] Re: what is inverse of mzero and return?

(Sorry about the recurrent self answers)

Maybe (not sure) it is sensible to sapecify return::(a -> IO a), as an action with no side effects such that

return x === return x iff x === x. return x === return y iff x === y <-- this is what I meant to write.

But even that is not enough, should be: "return x is an action with no side effects and that always returns x" The previous specification is be a consequence of this one, and it failed to specify that the returned value was always x. J.A.