GADT problems

[Jason Dagit]

On Mon, Sep 15, 2008 at 4:18 AM, Simon Peyton-Jones
<simonpj at microsoft.com> wrote:
>
> If you can suggest improvements to the manual I'm all ears.  Notably, it says nothing about what "rigid" means or how it propagates.

A good solid definition of rigid would be nice.  You pointed me at a
paper on wobbly types that I found to be quite helpful in my
understanding of the type checking issues.  The paper told me that
roughly speaking rigid means explicit.  Once I was armed with just
that information I started tackling more and more of these type check
problems.

Thanks,
Jason