diff --git a/dotscape b/dotscape
index 43a368b..b2b71b4 100755
Binary files a/dotscape and b/dotscape differ
diff --git a/functional-core/app/app-init.sml b/functional-core/app/app-init.sml
index c4d3ac2..0888eb3 100644
--- a/functional-core/app/app-init.sml
+++ b/functional-core/app/app-init.sml
@@ -24,6 +24,8 @@ struct
       , mouseX = 0.0
       , mouseY = 0.0
       , showGraph = true
+      , arrowX = 0
+      , arrowY = 0
       }
     end
 
diff --git a/functional-core/app/app-type.sml b/functional-core/app/app-type.sml
index 38d7045..50150ba 100644
--- a/functional-core/app/app-type.sml
+++ b/functional-core/app/app-type.sml
@@ -15,6 +15,7 @@ sig
     , y3: Real32.real
     }
 
+
   type app_type =
     { triangles: triangle list
     , triangleStage: triangle_stage
@@ -24,9 +25,11 @@ sig
     , yClickPoints: Real32.real vector
     , undo: (Real32.real * Real32.real) list
     , redo: (Real32.real * Real32.real) list
+    , showGraph: bool
     , mouseX: Real32.real
     , mouseY: Real32.real
-    , showGraph: bool
+    , arrowX: int
+    , arrowY: int
     }
 end
 
@@ -64,8 +67,10 @@ struct
     , yClickPoints: Real32.real vector
     , undo: (Real32.real * Real32.real) list
     , redo: (Real32.real * Real32.real) list
+    , showGraph: bool
     , mouseX: Real32.real
     , mouseY: Real32.real
-    , showGraph: bool
+    , arrowX: int
+    , arrowY: int
     }
 end
diff --git a/functional-core/app/app-update.sml b/functional-core/app/app-update.sml
index a70ce8e..5f04f04 100644
--- a/functional-core/app/app-update.sml
+++ b/functional-core/app/app-update.sml
@@ -59,9 +59,8 @@ struct
                  val drawMsg = DRAW_DOT drawVec
 
                  val newTriangleStage = FIRST {x1 = hpos, y1 = vpos}
-                 val model =
-                   AppWith.addTriangleStage
-                     (model, newTriangleStage, newUndoTuple)
+                 val model = AppWith.addTriangleStage
+                   (model, newTriangleStage, newUndoTuple, hIdx, vIdx)
                in
                  (model, DRAW drawMsg)
                end
@@ -73,16 +72,15 @@ struct
 
                  val newTriangleStage = SECOND
                    {x1 = x1, y1 = y1, x2 = hpos, y2 = vpos}
-                 val model =
-                   AppWith.addTriangleStage
-                     (model, newTriangleStage, newUndoTuple)
+                 val model = AppWith.addTriangleStage
+                   (model, newTriangleStage, newUndoTuple, hIdx, vIdx)
                in
                  (model, DRAW drawMsg)
                end
            | SECOND {x1, y1, x2, y2} =>
                let
                  val model = AppWith.addTriangle
-                   (model, x1, y1, x2, y2, hpos, vpos, newUndoTuple)
+                   (model, x1, y1, x2, y2, hpos, vpos, newUndoTuple, hIdx, vIdx)
                  val drawVec = Triangles.toVector model
                  val drawMsg = DRAW_TRIANGLES_AND_RESET_DOTS drawVec
                in
diff --git a/functional-core/app/app-with.sml b/functional-core/app/app-with.sml
index 169cf51..4f057ae 100644
--- a/functional-core/app/app-with.sml
+++ b/functional-core/app/app-with.sml
@@ -27,7 +27,11 @@ sig
    * and also add new click position to undo stack.
    *)
   val addTriangleStage:
-    AppType.app_type * AppType.triangle_stage * (Real32.real * Real32.real)
+    AppType.app_type
+    * AppType.triangle_stage
+    * (Real32.real * Real32.real)
+    * int
+    * int
     -> AppType.app_type
 
   val addTriangle:
@@ -39,6 +43,8 @@ sig
     * Real32.real
     * Real32.real
     * (Real32.real * Real32.real)
+    * int
+    * int
     -> AppType.app_type
 
   val useTriangles: AppType.app_type * AppType.triangle list -> AppType.app_type
@@ -50,7 +56,8 @@ struct
 
   (* add to undo, clear redo *)
   fun addTriangleStage
-    (app: app_type, newTriangleStage: triangle_stage, newUndoHd) : app_type =
+    (app: app_type, newTriangleStage: triangle_stage, newUndoHd, arrowX, arrowY) :
+    app_type =
     let
       val
         { triangleStage = _
@@ -61,9 +68,11 @@ struct
         , windowHeight
         , undo
         , redo = _
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX = _
+        , arrowY = _
         } = app
 
       val newUndo = newUndoHd :: undo
@@ -76,13 +85,17 @@ struct
       , yClickPoints = yClickPoints
       , windowWidth = windowWidth
       , windowHeight = windowHeight
+      , showGraph = showGraph
       , mouseX = mouseX
       , mouseY = mouseY
-      , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
-  fun addTriangle (app: app_type, x1, y1, x2, y2, x3, y3, newUndoHd) : app_type =
+  fun addTriangle
+    (app: app_type, x1, y1, x2, y2, x3, y3, newUndoHd, arrowX, arrowY) :
+    app_type =
     let
       val
         { triangles
@@ -93,9 +106,11 @@ struct
         , windowHeight
         , undo
         , redo = _
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX = _
+        , arrowY = _
         } = app
 
       val newTriangle = {x1 = x1, y1 = y1, x2 = x2, y2 = y2, x3 = x3, y3 = y3}
@@ -110,9 +125,11 @@ struct
       , yClickPoints = yClickPoints
       , windowWidth = windowWidth
       , windowHeight = windowHeight
+      , showGraph = showGraph
       , mouseX = mouseX
       , mouseY = mouseY
-      , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -129,9 +146,11 @@ struct
         , triangleStage
         , undo
         , redo
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX
+        , arrowY
         } = app
 
       val xClickPoints = ClickPoints.generate (wStart, wFinish)
@@ -145,9 +164,11 @@ struct
       , windowHeight = windowHeight
       , undo = undo
       , redo = redo
+      , showGraph = showGraph
       , mouseX = mouseX
       , mouseY = mouseY
-      , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -188,6 +209,8 @@ struct
         , undo
         , redo
         , showGraph
+        , arrowX
+        , arrowY
         } = app
     in
       { mouseX = mouseX
@@ -201,6 +224,8 @@ struct
       , undo = undo
       , redo = redo
       , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -216,9 +241,11 @@ struct
         , windowHeight
         , undo
         , redo
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX
+        , arrowY
         } = app
 
       val newUndo =
@@ -236,9 +263,11 @@ struct
       , yClickPoints = yClickPoints
       , windowWidth = windowWidth
       , windowHeight = windowHeight
+      , showGraph = showGraph
       , mouseX = mouseX
       , mouseY = mouseY
-      , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -254,9 +283,11 @@ struct
         , windowHeight
         , undo
         , redo
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX
+        , arrowY
         } = app
 
       val newUndo = newUndoHd :: undo
@@ -273,9 +304,11 @@ struct
       , yClickPoints = yClickPoints
       , windowWidth = windowWidth
       , windowHeight = windowHeight
+      , showGraph = showGraph
       , mouseX = mouseX
       , mouseY = mouseY
-      , showGraph = showGraph
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -292,6 +325,8 @@ struct
         , redo
         , mouseX
         , mouseY
+        , arrowX
+        , arrowY
         , showGraph = _
         } = app
     in
@@ -306,6 +341,8 @@ struct
       , windowHeight = windowHeight
       , mouseX = mouseX
       , mouseY = mouseY
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 
@@ -318,9 +355,11 @@ struct
         , windowHeight
         , undo
         , redo
+        , showGraph
         , mouseX
         , mouseY
-        , showGraph
+        , arrowX
+        , arrowY
         , triangles = _
         , triangleStage = _
         } = app
@@ -338,6 +377,8 @@ struct
       , windowHeight = windowHeight
       , mouseX = mouseX
       , mouseY = mouseY
+      , arrowX = arrowX
+      , arrowY = arrowY
       }
     end
 end