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diff --git a/prolog/problems/trees/insertbt_3/en.py b/prolog/problems/trees/insertbt_3/en.py
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+id = 138
+name = 'insertBT/3'
+slug = 'insert an element into a binary tree'
+
+description = '''\
+<p><code>insertBT(X, T, NewT)</code>: the binary tree <code>NewT</code> is obtained from <code>T</code> by inserting the element <code>X</code> at a certain position. This is the opposite of the predicate <code>deleteBT/3</code>. Your code should generate all valid solutions.</p>
+<pre>
+  ?- insertBT(2, b(nil,1,nil), T).
+    T = b(b(nil,1,nil),2,nil) ;
+    T = b(nil,2,b(nil,1,nil)) ;
+    T = b(b(nil,2,nil),1,nil) ;
+    T = b(nil,1,b(nil,2,nil)).
+</pre>'''
+
+hint = {}