fix bug in big-squares

before, (big-squares 2 2 2) or even (big-squares 3 3 4) would fail

1/1/jord/exercises.org

@@ -49,7 +49,10 @@ largest numbers among three
 
   (define (middle? a x y)
     (or (and (> a x) (< a y))
-	(and (< a x) (> a y))))
+	(and (< a x) (> a y))
+	(and (= a x) (< a y))
+	(and (= a y) (< a x))
+	(and (= a y) (= a x))))
 
   (define (middle x y z)
     (cond ((middle? x y z) x)
@@ -60,12 +63,12 @@ largest numbers among three
     (+ (square (biggest a b c))
        (square (middle a b c))))
 
-  (big-squares 5 9 2)
+  (big-squares 3 5 2)
 
 #+END_SRC
 
 #+RESULTS:
-: 106
+: 34
 
 * 1.4