diff --git a/prism/src/pta/DBMList.java b/prism/src/pta/DBMList.java
index 7a0b2048..8082f7ca 100644
--- a/prism/src/pta/DBMList.java
+++ b/prism/src/pta/DBMList.java
@@ -434,6 +434,15 @@ public class DBMList extends NCZone
 		else return null;
 	}
 	
+	/**
+	 * Get the number of DBMs in this DBMList.
+	 * @return
+	 */
+	public int size()
+	{
+		return list.size();
+	}
+
 	/**
 	 * Clone this zone
 	 */
@@ -448,12 +457,14 @@ public class DBMList extends NCZone
 
 	// Standard Java methods
 
+	@Override
 	public int hashCode()
 	{
 		// Simple hash code
 		return list.size();
 	}
 
+	@Override
 	public boolean equals(Object o)
 	{
 		DBMList dbml;
@@ -477,6 +488,7 @@ public class DBMList extends NCZone
 
 	// To string methods
 
+	@Override
 	public String toString()
 	{
 		return "" + list;
@@ -530,10 +542,6 @@ public class DBMList extends NCZone
 		}
 	}
 	
-	public int size() {
-		return list.size();
-	}
-
 	// Test program for complementing big DBM lists
 	
 	public static void main(String args[])