diff --git a/fastlib/trunk/contrib/tqlong/GraphicalModel/logarithm.cc b/fastlib/trunk/contrib/tqlong/GraphicalModel/logarithm.cc
new file mode 100644
index 0000000000..ba33dce3fa
--- /dev/null
+++ b/fastlib/trunk/contrib/tqlong/GraphicalModel/logarithm.cc
@@ -0,0 +1,11 @@
+#include "gm.h"
+
+ostream& operator << (ostream& os, const GM_NAMESPACE::Logarithm& x)
+{
+  return os << "exp(" << x.logValue() << ") = " << x.originalValue();
+}
+
+GM_NAMESPACE::Logarithm log(const GM_NAMESPACE::Logarithm& x)
+{
+  return GM_NAMESPACE::Logarithm(x.logValue());
+}