Update my answers in ch4

Author: dwayne

ch4/ex1.txt

@@ -1,3 +1,5 @@
+Exercises: Mood Swing
+
 Given,
 
 data Mood = Blah | Woot deriving Show

ch4/ex2.txt

@@ -1,5 +1,5 @@
 1. not True && True
-2. not (x == 6)
+2. not (x == 6) ; N.B. x is not in scope
 3. (1 * 2) > 5
 4. "Merry" > "Happy"
 5. [1, 2, 3] ++ "look at me!" ; The lists contain different types

ch4/ex3.txt

@@ -1,3 +1,5 @@
+Chapter Exercises
+
 1. length :: [a] -> Int
 2. a) 5
    b) 3
@@ -11,8 +13,8 @@ However,
 
 6 / length [1, 2, 3] will return an error.
 
-Why? length [1, 2, 3] :: Int, but Int does not implement an instance of the
-Fractional typeclass.
+Why? length [1, 2, 3] :: Int, but Int is not an instance of the Fractional
+typeclass.
 
 4. div 6 (length [1, 2, 3])
 
@@ -53,7 +55,7 @@ myAbs n = if n >= 0 then n else (negate n)
 f :: (a, b) -> (c, d) -> ((b, d), (a, c))
 f x y = ((snd x, snd y), (fst x, fst y))
 
-Reading Syntax
+Correcting Syntax
 
 See syntax.hs