diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Activity.md b/wpf/Diagram/BPMN-Shapes/BPMN-Activity.md
index 7e2d0fb4e7..c98abd9017 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Activity.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Activity.md
@@ -51,7 +51,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -97,7 +97,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -154,7 +154,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -201,7 +201,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -257,7 +257,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -304,7 +304,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -351,7 +351,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -396,7 +396,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Connectors.md b/wpf/Diagram/BPMN-Shapes/BPMN-Connectors.md
index 352df2f51b..70c16296c2 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Connectors.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Connectors.md
@@ -54,7 +54,7 @@ SfDiagram diagram = new SfDiagram();
     TargetPoint = new Point(200, 100)
  };
  // Add the BpmnFlowViewModel into the Connectors's collection.
-(Diagram.Connectors as GroupCollection).Add(flow);
+(diagram.Connectors as GroupCollection).Add(flow);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -106,7 +106,7 @@ SfDiagram diagram = new SfDiagram();
     TargetPoint = new Point(200, 100)
  };
  // Add the BpmnFlowViewModel into the Connectors's collection.
-(Diagram.Connectors as GroupCollection).Add(flow);
+(diagram.Connectors as GroupCollection).Add(flow);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -157,7 +157,7 @@ SfDiagram diagram = new SfDiagram();
     TargetPoint = new Point(200, 100)
  };
  // Add the BpmnFlowViewModel into the Connectors's collection.
-(Diagram.Connectors as GroupCollection).Add(flow);
+(diagram.Connectors as GroupCollection).Add(flow);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Data-Object.md b/wpf/Diagram/BPMN-Shapes/BPMN-Data-Object.md
index 2c12cec0b0..89b4756af2 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Data-Object.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Data-Object.md
@@ -45,7 +45,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Data-Store.md b/wpf/Diagram/BPMN-Shapes/BPMN-Data-Store.md
index df20e8abae..4720936ed8 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Data-Store.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Data-Store.md
@@ -43,7 +43,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Event.md b/wpf/Diagram/BPMN-Shapes/BPMN-Event.md
index 9ec5356a51..63f6b82029 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Event.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Event.md
@@ -51,7 +51,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -96,7 +96,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Expanded-Sub-Process.md b/wpf/Diagram/BPMN-Shapes/BPMN-Expanded-Sub-Process.md
index 1b633a12a5..981a519ede 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Expanded-Sub-Process.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Expanded-Sub-Process.md
@@ -54,7 +54,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   IsExpandedSubProcess = true
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -144,7 +144,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
 // Add the connector into the Connector's collection.
 (group.Connectors as ConnectorCollection).Add(flow);
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -212,7 +212,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   LoopActivity = LoopCharacteristic.Standard
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -270,7 +270,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   IsCompensationActivity = true
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -320,7 +320,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   IsAdhocActivity = true
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -367,7 +367,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   SubProcessType = SubProcessType.Event
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Gateway.md b/wpf/Diagram/BPMN-Shapes/BPMN-Gateway.md
index 3344001204..f6dd9a9e4a 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Gateway.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Gateway.md
@@ -44,7 +44,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Group.md b/wpf/Diagram/BPMN-Shapes/BPMN-Group.md
index ad74aaaa4c..41e7e99e78 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Group.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Group.md
@@ -46,7 +46,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
   UnitHeight = 250,
  };
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
@@ -129,7 +129,7 @@ BpmnGroupViewModel group = new BpmnGroupViewModel()
 // Add the connector into the Connector's collection.
 (group.Connectors as ConnectorCollection).Add(flow);
  // Add the group into the Group's collection.
-(Diagram.Groups as GroupCollection).Add(group);
+(diagram.Groups as GroupCollection).Add(group);
 
 {% endhighlight %}
 {%  endtabs %}
diff --git a/wpf/Diagram/BPMN-Shapes/BPMN-Shapes.md b/wpf/Diagram/BPMN-Shapes/BPMN-Shapes.md
index d32bab0932..e309fc41a7 100644
--- a/wpf/Diagram/BPMN-Shapes/BPMN-Shapes.md
+++ b/wpf/Diagram/BPMN-Shapes/BPMN-Shapes.md
@@ -45,7 +45,7 @@ BpmnNodeViewModel node = new BpmnNodeViewModel()
 };
 
 // Add the node into the Node's collection.
-(Diagram.Nodes as NodeCollection).Add(node);
+(diagram.Nodes as NodeCollection).Add(node);
 
 {% endhighlight %}
 {%  endtabs %}