Fixed variable scoping bug.

nltk/sem/relextract.py

@@ -377,14 +377,14 @@ def ieer_headlines():
 
     from nltk.corpus import ieer
     from nltk.tree import Tree
-
+    
     print("IEER: First 20 Headlines")
-    print("=" * 45)
-
-    trees = [doc.headline for file in ieer.fileids() for doc in ieer.parsed_docs(file)]
+    print("=" * 45)  
+    
+    trees = [(doc.docno, doc.headline) for file in ieer.fileids() for doc in ieer.parsed_docs(file)]
     for tree in trees[:20]:
         print()
-        print("%s:\n%s" % (doc.docno, tree))
+        print("%s:\n%s" % tree)