X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FForest.java;h=e53bfcb10e32111f87c3038254d3a82390a2b4c9;hp=7fde86e681d3ec06854a39ec798576b0b9430559;hb=5ae7d4fd7c53dab6df9aae2e42579efabf66f49e;hpb=1b5d6cf8ab6963d50c168c9daeb7887b45a343ea

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index 7fde86e..e53bfcb 100644
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -127,7 +127,20 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.Body<T>>*/
         public Ref() { }
 
         public Tree<T> expand1() throws Ambiguous {
-            if (hp.size() > 1) throw new Ambiguous(this);
+            if (hp.size() > 1) {
+                HashSet<Forest<T>> hf0 = new HashSet<Forest<T>>();
+                Iterator<Forest<T>> ih = hp.iterator();
+                ih.next().gather(hf0);
+                for(Forest<T> f : hp) {
+                    HashSet<Forest<T>> hf1 = new HashSet<Forest<T>>();
+                    f.gather(hf1);
+                    hf0.retainAll(hf1);
+                }
+                HashSet<Tree<T>> ht = new HashSet<Tree<T>>();
+                expand(ht, hf0, new Tree(null, "*"));
+                throw new Ambiguous((Forest<?>)this,
+                                    (HashSet<Tree<?>>)(Object)ht);
+            }
             return hp.iterator().next().expand1();
         }