diff --git a/lisp/compound-interest-test.lisp b/lisp/compound-interest-test.lisp
index e9f8de7..1031947 100644
--- a/lisp/compound-interest-test.lisp
+++ b/lisp/compound-interest-test.lisp
@@ -5,43 +5,43 @@
   (list
 
     (defun many-years-with-no-interest-rate ()
-      (eq (compound-interest 100000 0 10) 100000)
+      (assert= 100000 (compound-interest 100000 0 10))
     )
 
     (defun no-years-with-positive-interest-rate ()
-      (eq (compound-interest 100000 10 0) 100000)
+      (assert= 100000 (compound-interest 100000 10 0))
     )
 
     (defun one-year-with-positive-interest-rate ()
-      (eq (compound-interest 100000 5 1) 105000)
+      (assert= 105000 (compound-interest 100000 5 1))
     )
 
     (defun two-years-with-positive-interest-rate ()
-      (eq (compound-interest 100000 5 2) 110250)
+      (assert= 110250 (compound-interest 100000 5 2))
     )
 
     (defun three-years-with-positive-interest-rate ()
-      (eq (compound-interest 100000 5 3) 115763)
+      (assert= 115763 (compound-interest 100000 5 3))
     )
 
     (defun four-years-with-positive-interest-rate ()
-      (eq (compound-interest 100000 5 4) 121551)
+      (assert= 121551 (compound-interest 100000 5 4))
     )
 
     (defun one-year-with-negative-interest-rate ()
-      (eq (compound-interest 100000 (- 5) 1) 95000)
+      (assert= 95000 (compound-interest 100000 (- 5) 1))
     )
 
     (defun two-years-with-negative-interest-rate ()
-      (eq (compound-interest 100000 (- 5) 2) 90250)
+      (assert= 90250 (compound-interest 100000 (- 5) 2))
     )
 
     (defun three-years-with-negative-interest-rate ()
-      (eq (compound-interest 100000 (- 5) 3) 85737)
+      (assert= 85737 (compound-interest 100000 (- 5) 3))
     )
 
     (defun four-years-with-negative-interest-rate ()
-      (eq (compound-interest 100000 (- 5) 4) 81450)
+      (assert= 81450 (compound-interest 100000 (- 5) 4))
     )
 
   )
diff --git a/lisp/compound-interest.lisp b/lisp/compound-interest.lisp
index 61ca082..0817706 100644
--- a/lisp/compound-interest.lisp
+++ b/lisp/compound-interest.lisp
@@ -3,14 +3,14 @@
 (defun percent (n percent)
   (cond
     ((> percent 0) (/ (+ (* n percent) 50) 100))
-    (t (/ (- (* n percent) 50) 100))
+    (T (/ (- (* n percent) 50) 100))
   )
 )
 
 (defun compound-interest (principal rate years)
   (cond
     ((= years 0) principal)
-    (t (compound-interest (+ principal (percent principal rate))
+    (T (compound-interest (+ principal (percent principal rate))
                           rate
                           (decrement years)
        )
diff --git a/lisp/compound-test.lisp b/lisp/compound-test.lisp
deleted file mode 100644
index 8179405..0000000
--- a/lisp/compound-test.lisp
+++ /dev/null
@@ -1,33 +0,0 @@
-(load "unit-test.lisp")
-(load "compound.lisp")
-
-(unit
-  (list
-
-    (defun many-years-with-no-interest-rate ()
-      (eq (compound 100000 0 10) 100000)
-    )
-
-    (defun no-years-with-positive-interest-rate ()
-      (eq (compound 100000 10 0) 100000)
-    )
-
-    (defun one-year-with-positive-interest-rate ()
-      (eq (compound 100000 5 1) 105000)
-    )
-
-    (defun two-years-with-positive-interest-rate ()
-      (eq (compound 100000 5 2) 110250)
-    )
-
-    (defun three-years-with-positive-interest-rate ()
-      (eq (compound 100000 5 3) 115763)
-    )
-
-    (defun four-years-with-positive-interest-rate ()
-      (eq (compound 100000 5 4) 121551)
-    )
-
-  )
-)
-
diff --git a/lisp/compound.lisp b/lisp/compound.lisp
deleted file mode 100644
index 0f46729..0000000
--- a/lisp/compound.lisp
+++ /dev/null
@@ -1,14 +0,0 @@
-(defun compound (principal interest-rate years)
-  (cond
-    ((= years 0) principal)
-    (t (let ( (previous-principal (compound principal interest-rate (- years 1))) )
-            (+ previous-principal
-               (/ (+ (* previous-principal
-                        interest-rate)
-                     50)
-                  100)
-            )
-       )
-    )
-  )
-)
diff --git a/lisp/unit-test.lisp b/lisp/unit-test.lisp
index 31d2642..896257b 100644
--- a/lisp/unit-test.lisp
+++ b/lisp/unit-test.lisp
@@ -12,5 +12,12 @@
 )
 
 (defun unit (test-suite)
-  (apply 'and (run-test-suite test-suite))
+  (eval (cons 'and (run-test-suite test-suite)))
+)
+
+(defun assert= (expected actual)
+  (cond
+    ((= expected actual) T)
+    (T (print (list expected 'is 'not actual)) nil)
+  )
 )