diff --git a/ch01-welcome-repl-interactions.clj b/ch01-welcome-repl-interactions.clj
index 9e3ed8d..c5477b5 100644
--- a/ch01-welcome-repl-interactions.clj
+++ b/ch01-welcome-repl-interactions.clj
@@ -1,4 +1,3 @@
-
 ;-----
 (defn average
   [numbers]
@@ -542,10 +541,12 @@ p
 
 ;-----
 (letfn [(odd? [n]
-          (even? (dec n)))
+          (if (zero? n)
+            false
+            (even? (dec n))))
         (even? [n]
           (or (zero? n)
-            (odd? (dec n))))]
+              (odd? (dec n))))]
   (odd? 11))
 ;= true
 
diff --git a/ch03-collections-repl-interactions.clj b/ch03-collections-repl-interactions.clj
index a666219..810f7e8 100644
--- a/ch03-collections-repl-interactions.clj
+++ b/ch03-collections-repl-interactions.clj
@@ -575,7 +575,7 @@ sm
 ;-----
 (defn compare-magnitude
   [a b]
-  (- (magnitude a) (magnitude b)))
+  (neg? (- (magnitude a) (magnitude b))))
 
 ((comparator compare-magnitude) 10 10000)
 ;= -1
@@ -1456,7 +1456,7 @@ b
            unvisited (disj (set (keys paths)) start-loc)]
       (if-let [loc (when-let [s (seq unvisited)] (rand-nth s))]
         (let [walk (iterate (comp rand-nth paths) loc)
-              steps (zipmap (take-while unvisited walk) (next walk))]<8>
+              steps (zipmap (take-while unvisited walk) (next walk))]
           (recur (reduce disj walls (map set steps))
             (reduce disj unvisited (keys steps))))
         walls))))
@@ -1518,7 +1518,7 @@ b
         deltas [[2 0] [1 1] [-1 1]]]
     (set (for [v vertices d deltas f [+ -]
                :let [w (vertices (map f v d))]
-               :when w] #{v w}))
+               :when w] #{v w}))))
 
 (defn- hex-outer-walls
   [w h]
@@ -1527,7 +1527,7 @@ b
         deltas [[2 0] [1 1] [-1 1]]]
     (set (for [v vertices d deltas f [+ -]
                :let [w (map f v d)]
-               :when (not (vertices w))] #{v (vec w)}))
+               :when (not (vertices w))] #{v (vec w)}))))
 
 (defn hex-draw
   [w h maze]
diff --git a/ch06-datatypes-repl-interactions.clj b/ch06-datatypes-repl-interactions.clj
index 2b55d9a..1d327ed 100644
--- a/ch06-datatypes-repl-interactions.clj
+++ b/ch06-datatypes-repl-interactions.clj
@@ -551,7 +551,7 @@ Point
           [[(:x pt)] [(:y pt)]])
    :cols (fn [pt]
            [[(:x pt) (:y pt)]])
-   :dims (fn [pt] [2 1]))
+   :dims (fn [pt] [2 1])})
 
 
 ;-----
diff --git a/ch12-patterns-repl-interactions.clj b/ch12-patterns-repl-interactions.clj
index 3c19387..41ef5fb 100644
--- a/ch12-patterns-repl-interactions.clj
+++ b/ch12-patterns-repl-interactions.clj
@@ -80,7 +80,7 @@ class MyApp {
 (defprotocol Bark
   (bark [this]))
 
-(defrecord Chihuahua [weight price]
+(defrecord Chihuahua []
   Bark
   (bark [this] "Yip!"))
 
diff --git a/ch14-rdbms-repl-interactions.clj b/ch14-rdbms-repl-interactions.clj
index 97f03ae..0e6cb61 100644
--- a/ch14-rdbms-repl-interactions.clj
+++ b/ch14-rdbms-repl-interactions.clj
@@ -1,4 +1,3 @@
-
 ;-----
 (require '[clojure.java.jdbc :as jdbc])
 ;= nil
@@ -12,13 +11,13 @@
 {:classname "com.mysql.jdbc.Driver"
  :subprotocol "mysql"
  :subname "//localhost:3306/databasename"
- :username "login"
+ :user "login"
  :password "password"}
 
 
 ;-----
 {:datasource datasource-instance
- :username "login"
+ :user "login"
  :password "password"}