You can achieve a certain amount of type disequality in Haskell. It isn't necessarily easy or sufficient for all purposes. There is a type family that returns a

You can achieve a certain amount of type disequality in Haskell. It isn't necessarily easy or sufficient for all purposes. There is a type family that returns a type level Bool for equality here. https://hackage.haskell.org/package/base-4.12.0.0/docs/Data-Type-Equality.html https://hackage.haskell.org/package/base-4.12.0.0/docs/Data-... There are some older techniques here http://okmij.org/ftp/Haskell/typeEQ.html http://okmij.org/ftp/Haskell/typeEQ.html