[Haskell-beginners] Fwd: Overlapping instances via Nat-kind

Dannyu NDos ndospark320 at gmail.com
Wed Jan 2 08:48:21 UTC 2019

(Message re-sent)
Hi everyone. I'm not so skillful with GADTs and DataKinds, so I assume this
mailing list is appropriate to post on.

Basically, I wanted to do GADT like this (involving GHC.TypeNats):

data Symmetric (n :: Nat) where
    S1 :: Symmetric 1
    (:.) :: (KnownNat n, 2 <= n) => Cyclic n -> Symmetric (n-1) -> Symmetric n

But I had some issues with this. The full question is here (on Stack


Dannyu NDos
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