Oh I see it is whitespace sensitive:

"type t = [|s]" fails
"type t = [ |s]" works


On Thu, Oct 1, 2015 at 6:35 PM, Daniel Bünzli <daniel.buenzli@erratique.ch>
wrote:

> Le jeudi, 1 octobre 2015 à 23:28, Ashish Agarwal a écrit :
> > On Thu, Oct 1, 2015 at 6:20 PM, Thomas Refis <thomas.refis@gmail.com
> (mailto:thomas.refis@gmail.com)> wrote:
> > > Note the you could also do "type t = [ | s ]"
> >
> > Actually I had tried that, but it doesn't work.
>
> It does here (4.02.3).
>
> Daniel
>
>
>