import Prelude hiding (gcd, lcm)

{- Exercise 4.1 -}

-- 4.1.1
gcd :: Integer -> Integer -> Integer
gcd a b = undefined

-- 4.1.2
gcd_eff :: Integer -> Integer -> Integer
gcd_eff a b = undefined


{- Exercise 4.2 -}

-- 4.2.1
lcm :: Integer -> Integer -> Integer
lcm a b = undefined

lcm_aux :: Integer -> Integer -> Integer -> Integer -> Integer
lcm_aux ma mb a b = undefined

-- 4.2.2
lcm2 :: Integer -> Integer -> Integer
lcm2 a b = undefined

lcm2_aux :: Integer -> Integer -> Integer -> Integer
lcm2_aux m a b = undefined

-- 4.2.3
lcm3 :: Integer -> Integer -> Integer
lcm3 a b = undefined


{- Exercise 4.3 -}

-- 4.3.1
data Mountain

isHigher :: Mountain -> Mountain -> Bool
isHigher = undefined


-- 4.3.2
altitude :: Mountain -> Integer
altitude = undefined

isHigher2 :: Mountain -> Mountain -> Bool
isHigher2 = undefined