It does not directly answer your question, but are you aware of Pie?

https://github.com/david-christiansen/pie-hs

On Thu, Jun 20, 2019 at 1:45 PM Andrew Martin <andrew.thaddeus@gmail.com> wrote:
>
> I just read through Lennart's paper on Cayenne, which was written in Haskell. It would be informative for me to look at the source code for a simple dependently typed language like this. (The paper claims the typechecker is only around 5000 LoC.) However, I cannot find the source code anywhere. Has it been devoured by the cruel jaws of the ephemeral web, or does someone out there still have a copy of it?
>
> --
> -Andrew Thaddeus Martin
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