X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=Robust%2Fsrc%2FUtil%2FLattice.java;h=b76b7bb0185f4ca7ee3fef7031f7792843d99e09;hb=cbc13efe1afc46ef542fde526361b4911d3da0e1;hp=aea74773d7ca8936c00105a61a8d6cd6283423bd;hpb=5e5c10a2592a9acd282a1ae27bdf7468beb12e90;p=IRC.git

diff --git a/Robust/src/Util/Lattice.java b/Robust/src/Util/Lattice.java
index aea74773..b76b7bb0 100644
--- a/Robust/src/Util/Lattice.java
+++ b/Robust/src/Util/Lattice.java
@@ -66,10 +66,15 @@ public class Lattice<T> {
   }
 
   public boolean put(T key, T value) {
+    
+    if(isGreaterThan(key, value)){
+      // this relation already exists
+      return false;
+    }
+    
     Set<T> s;
 
     Set<T> topNeighbor = table.get(top);
-
     if (table.containsKey(key)) {
       s = table.get(key);
     } else {
@@ -90,7 +95,10 @@ public class Lattice<T> {
       }
 
       // if value is already connected with top, it is no longer to be
-      topNeighbor.remove(value);
+      if(!key.equals(top)){
+        topNeighbor.remove(value);  
+      }
+      
 
       // if key is already connected with bottom,, it is no longer to be
       if (!value.equals(getBottomItem())) {