[Haskell-cafe] Mux, was Re: Clearly, Haskell is ill-founded

[Derek Elkins]

On Tue, 2007-07-17 at 13:23 +0100, Conor McBride wrote:
> On 16 Jul 2007, at 19:53, Stefan Holdermans wrote:
> 
> > I wrote:
> >
> >> I came up with [...]
> >
> > apfelmus' solution is of course more elegant, but I guess it boils  
> > down to the same basic idea.
> 
> Yep, you need inductive data to guarantee that you eventually stop
> spitting out one sort of thing and flip over to the other. Here's my
> version.
> 
> Mux...
> 
>  > data{-codata-} Mux x y = Mux (Muy x y)
> 
> ...is defined by mutual induction with...
> 
>  > data Muy x y = y :- Muy x y | x :~ Mux y x

As an inductive data type, isn't this empty?