diff --git a/DeedyDesigner/Deedy.Activity/Contract/Interface/ICombinedElement.cs b/DeedyDesigner/Deedy.Activity/Contract/Interface/ICombinedElement.cs
new file mode 100644
index 0000000..7de00fc
--- /dev/null
+++ b/DeedyDesigner/Deedy.Activity/Contract/Interface/ICombinedElement.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Deedy.Activity
+{
+    public interface ICombinedElement : IDeedyElement
+    {
+        public DeedyElementCollection Elements { get; set; }
+    }
+}
diff --git a/DeedyDesigner/Deedy.Activity/Contract/Interface/IContainerElement.cs b/DeedyDesigner/Deedy.Activity/Contract/Interface/IContainerElement.cs
index 6ba813b..b53c7e9 100644
--- a/DeedyDesigner/Deedy.Activity/Contract/Interface/IContainerElement.cs
+++ b/DeedyDesigner/Deedy.Activity/Contract/Interface/IContainerElement.cs
@@ -1,14 +1,15 @@
 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace Deedy.Activity
 {
-    public interface IContainerElement : IDeedyElement
+    public interface IContainerElement : ICombinedElement
     {
-        public DeedyElementCollection Elements { get; set; }
+        public void Append(IDeedyElement deedyElement);
+        public void Remove(IDeedyElement deedyElement);
+        public void SwapIndex(IDeedyElement element1, IDeedyElement element2);
     }
 }
diff --git a/DeedyDesigner/Deedy.Activity/Contract/Interface/IVariableContainer.cs b/DeedyDesigner/Deedy.Activity/Contract/Interface/IVariableContainer.cs
deleted file mode 100644
index cd7af67..0000000
--- a/DeedyDesigner/Deedy.Activity/Contract/Interface/IVariableContainer.cs
+++ /dev/null
@@ -1,15 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Deedy.Activity
-{
-    public interface IVariableContainer : IContainerElement
-    {
-        public void Append(IDeedyElement deedyElement);
-        public void Remove(IDeedyElement deedyElement);
-        public void SwapIndex(IDeedyElement element1, IDeedyElement element2);
-    }
-}
diff --git a/DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombineDiagram.cs b/DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombinedDiagram.cs
similarity index 63%
rename from DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombineDiagram.cs
rename to DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombinedDiagram.cs
index 49f78c2..1811b87 100644
--- a/DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombineDiagram.cs
+++ b/DeedyDesigner/Deedy.Activity/DeedyAction/FlowAction/CombinedDiagram.cs
@@ -6,8 +6,8 @@ using System.Threading.Tasks;
 
 namespace Deedy.Activity
 {
-    public abstract class CombineDiagram : FlowAction
+    public abstract class CombinedDiagram : FlowAction
     {
-        public CombineDiagram() { }
+        public CombinedDiagram() { }
     }
 }
diff --git a/DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombineFunction.cs b/DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombinedFunction.cs
similarity index 63%
rename from DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombineFunction.cs
rename to DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombinedFunction.cs
index ecae849..7b194d5 100644
--- a/DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombineFunction.cs
+++ b/DeedyDesigner/Deedy.Activity/DeedyAction/FuncAction/CombinedFunction.cs
@@ -6,8 +6,8 @@ using System.Threading.Tasks;
 
 namespace Deedy.Activity
 {
-    public abstract class CombineFunction : FuncAction
+    public abstract class CombinedFunction : FuncAction
     {
-        public CombineFunction() { }
+        public CombinedFunction() { }
     }
 }
diff --git a/DeedyDesigner/Deedy.Activity/DeedyVisual/IDeedyLayout.cs b/DeedyDesigner/Deedy.Activity/DeedyVisual/IDeedyLayout.cs
index c0c65c4..8ddae95 100644
--- a/DeedyDesigner/Deedy.Activity/DeedyVisual/IDeedyLayout.cs
+++ b/DeedyDesigner/Deedy.Activity/DeedyVisual/IDeedyLayout.cs
@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace Deedy.Activity
 {
-    public interface IDeedyLayout : IVariableContainer
+    public interface IDeedyLayout : IContainerElement
     {
     }
 }