convertType (HsExplicitTupleTy _PlaceHolders tys) =
  case tys of
    []   -> pure $ Var "tt"
    [ty] -> convertLType ty
    _    -> foldl1 (App2 $ Var "pair") <$> traverse convertLType tys
convertType (HsExplicitTupleTy _PlaceHolders tys) =
  case tys of
    []   -> pure $ Var "tt"
    [ty] -> convertLType ty
    _    -> foldl1 (App2 $ Var "pair") <$> traverse convertLType tys
convertType (HsExplicitTupleTy _PlaceHolders tys) =
  case tys of
    []   -> pure $ Var "tt"
    [ty] -> convertLType ty
    _    -> foldl1 (App2 $ Var "pair") <$> traverse convertLType tys