Очепятки в книге по функциональному программированию

data Combinator = Var String
		| App Combinator Combinator
		| Lam String Combinator
  deriving Eq
instance Show Combinator where
  show (Var x)= x
  show (App x y) = case y of
     App _ _ -> showLam x ++
		"(" ++
		show y ++
		")"
     _	     -> showLam x ++
		showLam y
    where
	  showLam l@(Lam _ _) = "(" ++
	  			show l ++
				")"
	  showLam x	      = show x
  show (Lam x e) = "\\" ++
		   x ++
		   "."
		   ++ show e
i = Var "I"
k = Var "K"
s = Var "S"

free :: String -> Combinator -> Bool              
free x (Var y)	   = x == y
free x (App e1 e2) = free x e1 || free x e2
free x (Lam y e)   = free x e

transform :: Combinator -> Combinator
transform (Var x) = Var x
transform (App x y) = App (transform x)
                          (transform y)
transform (Lam x (Var y)) | x == y
  = i transform (Lam x e)
                          | (not . free x) e
  = App k (transform e) transform (Lam x l@(Lam y e))
                          | free x e
  = transform (Lam x (transform l))
transform (Lam x (App e1 e2))
  = App (App s (transform (Lam x e1)))
        (transform (Lam x e2))

transform (Lam x (Var y)) | x == y
  = i transform (Lam x e)

                          | (not . free x) e
  = App k (transform e) transform (Lam x l@(Lam y e))

transform :: Combinator -> Combinator
transform (Var x) = Var x
transform (App x y)= App (transform x)
						 (transform y)
transform e@(Lam x (Var y)) | x == y
  = App i (transform (Lam x e))
			  | (not . free x) e
  = App k (transform e) 
transform (Lam x l@(Lam y e))  | free x e
  = transform (Lam x (transform l))
transform (Lam x (App e1 e2))
  = App (App s (transform (Lam x e1)))
	(transform (Lam x e2))