mkTcNthCo :: Int -> TcCoercion -> TcCoercion
mkTcNthCo n (TcRefl r ty) = TcRefl r (tyConAppArgN n ty)
mkTcNthCo :: Int -> TcCoercion -> TcCoercion
mkTcNthCo n (TcRefl r ty) = TcRefl r (tyConAppArgN n ty)
mkTcNthCo n (TcRefl r ty) = TcRefl r (tyConAppArgN n ty)