From 03617c894b8d28daeab586fd11bde46ab723f4e3 Mon Sep 17 00:00:00 2001
From: Aaro Koivukangas <aaro.koivukangas@gmail.com>
Date: Wed, 24 Dec 2025 13:27:38 +0200
Subject: [PATCH] 5b ex7

---
 exercises/Set5b.hs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/exercises/Set5b.hs b/exercises/Set5b.hs
index a1e0063..69b26e6 100644
--- a/exercises/Set5b.hs
+++ b/exercises/Set5b.hs
@@ -155,7 +155,10 @@ cull val Empty = Empty
 --                     (Node 3 Empty Empty))   ==>   True
 
 isOrdered :: Ord a => Tree a -> Bool
-isOrdered = todo
+isOrdered (Node val t1 t2)
+  | allValues (val>) t1 && allValues (val<) t2 = isOrdered t1 && isOrdered t2
+  | otherwise = False
+isOrdered Empty = True
 
 ------------------------------------------------------------------------------
 -- Ex 8: a path in a tree can be represented as a list of steps that