Class diagramm was added

er.dot

@@ -15,7 +15,7 @@ graph ER {
 	{node [label = "σ_23"] s23};
 	{node [label = "σ_I"] sI};
 	
-	node [shape=ellipse]; "X"; "Y"; "Z";
+	node [shape=ellipse]; "X_1"; "X_2"; "X_3";
 	
 	node [shape=diamond,style=filled,color=lightgrey]; "С-Т";
 
@@ -32,9 +32,9 @@ graph ER {
 	props -- phaze;
 	props -- "С-Т" [label="m", len=1.00];
 	"С-Т" -- points [label="n",len=1.00];
-	points -- "X";
-	points -- "Y";
-	points -- "Z";
+	points -- "X_1";
+	points -- "X_2";
+	points -- "X_3";
 	
 	fontsize=20;
 }