diff --git a/Solver/function.h b/Solver/function.h
index 6a5ee284c1718bc39d774126c740030570882c0a..cc9d41a58312d2aa12609dc8e786959484b7f69c 100644
--- a/Solver/function.h
+++ b/Solver/function.h
@@ -198,6 +198,7 @@ class dataCacheDouble {
   {
     return (_iDependOn.find(&other)!=_iDependOn.end());
   }
+  inline std::vector<dataCacheDouble*> & getDirectDependencies() { return _directDependencies; }
 };
 
 class dataCacheMap {