fix a bug in exporting to uai format

packages/CLPBN/horus/FactorGraph.h

@@ -32,6 +32,7 @@ class VarNode : public Var
 };
 
 
+
 class FacNode
 {
   public:
@@ -60,14 +61,6 @@ class FacNode
 };
 
 
-struct CompVarId
-{
-  bool operator() (const Var* v1, const Var* v2) const
-  {
-    return v1->varId() < v2->varId();
-  }
-};
-
 
 class FactorGraph
 {
@@ -141,5 +134,15 @@ class FactorGraph
     VarMap varMap_;
 };
 
+
+
+struct sortByVarId
+{ 
+  bool operator()(VarNode* vn1, VarNode* vn2) { 
+    return vn1->varId() < vn2->varId();
+  }
+};
+
+
 #endif // HORUS_FACTORGRAPH_H