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 4d80d79..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
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"}