diff -r 2d537f8cd604 -r 04e312a7887e vm/src/test/java/org/apidesign/vm4brwsr/Numbers.java
--- a/vm/src/test/java/org/apidesign/vm4brwsr/Numbers.java	Fri Feb 01 06:09:18 2013 +0100
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/Numbers.java	Fri Feb 01 09:00:30 2013 +0100
@@ -72,6 +72,12 @@
         return Long.MAX_VALUE;
     }
     
+    public static long negL(byte[] arrValue) throws IOException {
+        ByteArrayInputStream isValue = new ByteArrayInputStream(arrValue);
+        DataInputStream disValue = new DataInputStream(isValue);
+        return (-disValue.readLong());
+    }
+    
     public static long addL(byte[] arrX, byte[] arrY) throws IOException {
         ByteArrayInputStream isX = new ByteArrayInputStream(arrX);
         DataInputStream disX = new DataInputStream(isX);