1 files changed, 3 insertions, 0 deletions
diff --git a/Project/Sum.h b/Project/Sum.h
index a99067e..49059f0 100644
--- a/Project/Sum.h
+++ b/Project/Sum.h
@@ -4,6 +4,7 @@
 #include "ControlElement.h"
 
 class SumForm;
+class ConnectionLine;
 
 class Sum : public ControlElement
 {
@@ -21,6 +22,8 @@ public:
     virtual std::vector<Signal> GetSignalList() const { return m_signalList; }
     virtual void SetSignalList(std::vector<Signal> signalList) { m_signalList = signalList; }
     
+    virtual bool Solve(double input);
+    
     virtual void UpdatePoints();
     void AddInNode();
     void RemoveInNode();