diff --git a/contain.c b/contain.c
index 48d7111..776a771 100644
--- a/contain.c
+++ b/contain.c
@@ -207,7 +207,7 @@ void activate (GtkApplication *app, gpointer user_data) {
   gtk_window_set_child (window, GTK_WIDGET(run_xor_edit_horizontal_pane));
   gtk_window_present (GTK_WINDOW (window));
 
-  gtk_notebook_set_current_page (run_notebook, 1);  //    @see  hot.c   2024-05-11  (line 68)
-  gtk_notebook_set_current_page (edit_notebook, 1);  //    @see  hot.c   2024-05-11  (line 68)
+  gtk_notebook_set_current_page (run_notebook, 0);  //    @see  hot.c   2024-05-11  (line 68)
+  gtk_notebook_set_current_page (edit_notebook, 0);  //    @see  hot.c   2024-05-11  (line 68)
 }
 
diff --git a/contain.o b/contain.o
index 0c2d6cc..7b1c36a 100644
Binary files a/contain.o and b/contain.o differ
diff --git a/display.c b/display.c
index 4139a91..3c0c275 100644
--- a/display.c
+++ b/display.c
@@ -78,15 +78,22 @@ GtkWidget *get_user_tree(){
 
 //  TODO  cliquer sur "RUN"  -->  affiche "STOP"  (et inversement)
 static GtkWidget *get_scroll_speed(){
-  GtkAdjustment *speed_adjust = gtk_adjustment_new (0, 0, 100, 1, 0, 0);
+  GtkAdjustment *speed_adjust = gtk_adjustment_new (100, 0, 100, 1, 0, 0);
   GtkWidget *scroll_speed = gtk_scrollbar_new (GTK_ORIENTATION_HORIZONTAL, speed_adjust);
-  gtk_widget_set_size_request (GTK_WIDGET (scroll_speed), 140, 2);
+  gtk_widget_set_size_request (GTK_WIDGET (scroll_speed), 120, 2);
   return scroll_speed;
 }
 
-static GtkBox *get_SPEED_box(){
+static GtkBox *get_UNDO_SPEED_box(){
   GtkBox *SPEED_box = GTK_BOX(gtk_box_new (GTK_ORIENTATION_VERTICAL, 0));
-  gtk_box_append (SPEED_box, GTK_WIDGET(gtk_label_new ("\n")));
+  gtk_box_append (SPEED_box, GTK_WIDGET(gtk_label_new ("< UNDO <\n")));
+  gtk_box_append (SPEED_box, get_scroll_speed());
+  return SPEED_box;
+}
+
+static GtkBox *get_DO_SPEED_box(){
+  GtkBox *SPEED_box = GTK_BOX(gtk_box_new (GTK_ORIENTATION_VERTICAL, 0));
+  gtk_box_append (SPEED_box, GTK_WIDGET(gtk_label_new ("> DO >\n")));
   gtk_box_append (SPEED_box, get_scroll_speed());
   return SPEED_box;
 }
@@ -94,9 +101,11 @@ static GtkBox *get_SPEED_box(){
 GtkBox *get_RUN_STOP_box(){
   GtkBox *RUN_STOP_box = GTK_BOX(gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 20));
 //  gtk_box_append (RUN_STOP_box, gtk_label_new ("\n"));
+//  gtk_box_append (RUN_STOP_box, GTK_WIDGET(gtk_label_new ("   <<<<   \n UNDO   ")));
+  gtk_box_append (RUN_STOP_box, GTK_WIDGET (get_UNDO_SPEED_box()));
+  gtk_box_append (RUN_STOP_box, GTK_WIDGET(gtk_label_new ("           STEP\n(show active rule) ")));
+  gtk_box_append (RUN_STOP_box, GTK_WIDGET (get_DO_SPEED_box()));
   gtk_box_append (RUN_STOP_box, GTK_WIDGET(gtk_label_new ("      R U N\n     S T O P")));
-  gtk_box_append (RUN_STOP_box, GTK_WIDGET (get_SPEED_box()));
-  gtk_box_append (RUN_STOP_box, GTK_WIDGET(gtk_label_new ("            STEP\n(show active rule)    ")));
 //  gtk_box_append (RUN_STOP_box, GTK_WIDGET(gtk_separator_new (GTK_ORIENTATION_VERTICAL)));
   return RUN_STOP_box;
 }
@@ -156,7 +165,7 @@ GtkProgressBar *get_ELAPSED_TIME_ProgressBar(){ //  To rename : DO - UNDO - REDO
   "\n<---  [buffer]  (simulation extensive time)  --->\n\
     supports DO - UNDO - REDO   functions\n");
   gtk_progress_bar_set_show_text (buffer, TRUE);
-  gtk_widget_set_size_request (GTK_WIDGET (buffer), W - 400, 0);
+  gtk_widget_set_size_request (GTK_WIDGET (buffer), W - 560, 0);
   return buffer;
 }
 
diff --git a/display.o b/display.o
index babc8e9..74b2ce7 100644
Binary files a/display.o and b/display.o differ
diff --git a/hot.o b/hot.o
index e7364e2..4aa6482 100644
Binary files a/hot.o and b/hot.o differ
diff --git a/myprogram b/myprogram
index 5c8ce38..fbe230d 100755
Binary files a/myprogram and b/myprogram differ