diff --git a/automaton.c b/automaton.c
index 48e5ed5..3de81f4 100644
--- a/automaton.c
+++ b/automaton.c
@@ -11,49 +11,68 @@
 static int choice_EXEC_EDIT = EXEC;
 static int choice_STATE_RULES_DATA = STATE;
 
-void set_EXEC_EDIT (int prescribed) {
-  choice_EXEC_EDIT = prescribed;
-  SWITCH_TO (choice_EXEC_EDIT, choice_STATE_RULES_DATA);
-}
-int  get_EXEC_EDIT () {return choice_EXEC_EDIT;}
-
-void set_STATE_RULES_DATA (int prescribed) {
-  choice_STATE_RULES_DATA = prescribed;
-  SWITCH_TO (choice_EXEC_EDIT, choice_STATE_RULES_DATA);
-}
-int  get_STATE_RULES_DATA () {return choice_STATE_RULES_DATA;}
-
 
 /******************************************************************************/
 /*                          T R A N S I T I O N S                             */
 /******************************************************************************/
 
-void SWITCH_TO (int choice_EXEC_EDIT, int choice_STATE_RULES_DATA)
-{
-  switch (choice_STATE_RULES_DATA) {
+void debug_printing (int prescribed, int sub_automaton);
 
-  case (STATE) :
-    choice_STATE_RULES_DATA = STATE;
-    if (choice_EXEC_EDIT ) choice_EXEC_EDIT = EXEC;
-    else                   choice_EXEC_EDIT = EDIT;
-    break;
-
-  case (RULES) :
-    choice_STATE_RULES_DATA = RULES;
-    if (choice_EXEC_EDIT ) choice_EXEC_EDIT = EXEC;
-    else                   choice_EXEC_EDIT = EDIT;
-    break;
-
-  case (DATA) :
-    choice_STATE_RULES_DATA = DATA;
-    if (choice_EXEC_EDIT ) choice_EXEC_EDIT = EXEC;
-    else                   choice_EXEC_EDIT = EDIT;
-    break;
-
-  default : printf("default in automaton.SWITCH_TO()\n");
+void set_EXEC_EDIT (int prescribed) {
+  if (choice_EXEC_EDIT != prescribed) {
+    debug_printing (prescribed, 0);
+    choice_EXEC_EDIT = prescribed;
   }
-
-  printf("SWITCH_TO  %d  X  %d   (EXEC_EDIT  X  STATE_RULES_DATA)\n",
-         choice_EXEC_EDIT,
-         choice_STATE_RULES_DATA);
 }
+
+void set_STATE_RULES_DATA (int prescribed) {
+  if (choice_STATE_RULES_DATA != prescribed) {
+    debug_printing (prescribed, 1);
+    choice_STATE_RULES_DATA = prescribed;
+  }
+}
+
+
+/******************************************************************************/
+/*                 G E T T E R S   &   D E B U G G E R S                      */
+/******************************************************************************/
+
+int  get_EXEC_EDIT () {return choice_EXEC_EDIT;}
+int  get_STATE_RULES_DATA () {return choice_STATE_RULES_DATA;}
+
+char *get_str_EXEC_EDIT (int value) {
+  switch (value) {
+  case (EXEC) : return "EXEC";
+  case (EDIT) : return "EDIT";
+  default : printf("default in automaton.get_EXEC_EDIT ()\n"); return NULL;
+  }
+}
+
+char *get_str_STATE_RULES_DATA (int value) {
+ switch (value) {
+  case (STATE) : return "STATE";
+  case (RULES) : return "RULES";
+  case (DATA)  : return "DATA";
+  default : printf("default in automaton.get_STATE_RULES_DATA ()\n"); return NULL;
+ }
+}
+
+void debug_printing (int prescribed, int sub_automaton) {
+  switch (sub_automaton) {
+  case (0) :  printf("switch >   %5s  X  %5s   <>   %5s  X  %5s\n",
+           get_str_EXEC_EDIT (choice_EXEC_EDIT),
+           get_str_STATE_RULES_DATA (choice_STATE_RULES_DATA),
+           get_str_EXEC_EDIT (prescribed),
+           get_str_STATE_RULES_DATA (choice_STATE_RULES_DATA));
+  break;
+  case (1) :  printf("switch >   %5s  X  %5s   <>   %5s  X  %5s\n",
+           get_str_EXEC_EDIT (choice_EXEC_EDIT),
+           get_str_STATE_RULES_DATA (choice_STATE_RULES_DATA),
+           get_str_EXEC_EDIT (choice_EXEC_EDIT),
+           get_str_STATE_RULES_DATA (prescribed));
+  break;
+  default : printf("default in automaton.debug_printing()\n");
+  }
+}
+
+
diff --git a/automaton.h b/automaton.h
index 750b25d..8126494 100644
--- a/automaton.h
+++ b/automaton.h
@@ -3,12 +3,14 @@
 
 enum choice_EXEC_EDIT { EXEC, EDIT };
 enum choice_STATE_RULES_DATA { STATE, RULES, DATA };
-          //  MEASURE, OBSERVE, INTERPRET, HELP, CONFIGURE };
+          //  MEASURE, OBSERVE, INTERPRET, HELP, CONFIGURE }; ?
 
 void set_EXEC_EDIT (int prescribed);
-int  get_EXEC_EDIT ();
-
 void set_STATE_RULES_DATA (int prescribed);
+
+int  get_EXEC_EDIT ();
 int  get_STATE_RULES_DATA ();
 
-void SWITCH_TO (int choice_EXEC_EDIT, int choice_STATE_RULES_DATA);
+char *get_str_EXEC_EDIT (int value);
+char *get_str_STATE_RULES_DATA (int value);
+
diff --git a/callback.c b/callback.c
index bda4d24..e164bc6 100644
--- a/callback.c
+++ b/callback.c
@@ -163,58 +163,53 @@ void on_axis_value_change(GtkAdjustment *adjustment, gpointer data)
 }
 
 
-
 /******************************************************************************/
 /*                             B U T T O N S                                  */
 /******************************************************************************/
+
 /*void on_toggle_MODEL_RUN_STOP (GtkWidget *btt_MODEL_RUN_STOP, gpointer data) {
   if (strcmp (gtk_button_get_label (GTK_BUTTON (btt_MODEL_RUN_STOP)), "  run  "))
        gtk_button_set_label (GTK_BUTTON (btt_MODEL_RUN_STOP), "  run  ");
   else gtk_button_set_label (GTK_BUTTON (btt_MODEL_RUN_STOP), " stop ");}*/
 
-void on_toggle_EXEC_EDIT (GtkWidget *btt_XOR_EXEC_EDIT, GtkWidget *window_child_STATE) {  //  *btt_MODEL_RUN_STOP) {
-  if (get_EXEC_EDIT()) {
-  gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "power-profile-balanced-rtl-symbolic");
-  set_EXEC_EDIT (EXEC);
+void on_toggle_EXEC_EDIT
+(GtkWidget *btt_XOR_EXEC_EDIT, gpointer user_data) {
+  if (get_EXEC_EDIT ()) {//  (strcmp (get_str_EXEC_EDIT(0), "EXEC")) {
+    gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "power-profile-balanced-rtl-symbolic");
+    set_EXEC_EDIT (EXEC);
   } else {
-  gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "preferences-system-symbolic");
-//  gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "emblem-ok-symbolic"); //   Transport Steam Engine   !!
-//  gtk_widget_set_sensitive (GTK_WIDGET (btt_MODEL_RUN_STOP), FALSE);
-//  gtk_box_append (GTK_BOX (window_child_STATE), GTK_WIDGET (get_SPACE_EDIT_controls_box()));
-  set_EXEC_EDIT (EDIT);
+  //  gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "preferences-system-symbolic");
+    gtk_button_set_icon_name (GTK_BUTTON (btt_XOR_EXEC_EDIT), "text-editor-symbolic");
+    set_EXEC_EDIT (EDIT);
   }
-//  gtk_window_present (GTK_WINDOW (main_window));
 }
 
 void on_toggle_STATE_RULES_DATA (GtkWidget *toggled_button, gpointer user_data) {
-  //  https://docs.gtk.org/gtk4/class.ToggleButton.html  <  f..k !   bad code ++
 
   const char *toggled_button_name = gtk_check_button_get_label (GTK_CHECK_BUTTON (toggled_button));
   int is_active = gtk_check_button_get_active (GTK_CHECK_BUTTON (toggled_button));
 
-  int is_state_active = ! strcmp (toggled_button_name, "state");
-  int is_rules_active = ! strcmp (toggled_button_name, "rules");
-  int is_data_active  = ! strcmp (toggled_button_name, "data analysis");
-  if (0 && is_active) printf (">  [%d]     %d, %d, %d    %14s\n",
-          is_active, is_state_active, is_rules_active, is_data_active, toggled_button_name);
+  if (! strcmp (toggled_button_name, "state"))         set_STATE_RULES_DATA (STATE);
+  if (! strcmp (toggled_button_name, "rules"))         set_STATE_RULES_DATA (RULES);
+  if (! strcmp (toggled_button_name, "data analysis")) set_STATE_RULES_DATA (DATA);
 
-  if (is_active) {
-         if (is_state_active) gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_STATE()));
-    else if (is_rules_active) gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_RULES()));
-    else if (is_data_active)  gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_DATA()));
-  }
+  if (is_active)
+    switch (get_STATE_RULES_DATA()) {
+    case (STATE) : gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_STATE())); break;
+    case (RULES) : gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_RULES())); break;
+    case (DATA)  : gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_DATA()));  break;
+    default :  printf("default in callback.on_toggle_STATE_RULES_DATA()\n");
+    }
 }
 
 void on_SAVE_CURRENT_MODEL_BEFORE_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data) {
   gtk_widget_set_sensitive (GTK_WIDGET (data), TRUE);
   printf ("callback.c (line 201)  -  SAVE_CURRENT_MODEL_BEFORE_EDITING\n");
-  SWITCH_TO (EXEC, STATE);
 }
 
 void on_DISCARD_CURRENT_MODEL_AND_START_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data) {
   gtk_window_close (GTK_WINDOW (data));
   printf ("callback.c (line 206)  -  DISCARD_CURRENT_MODEL_AND_START_EDITING\n");
-  SWITCH_TO (EXEC, RULES);
 }
 
 void on_WRITE_CURRENT_MODEL (GtkWidget *btt_WRITE_CURRENT_MODEL, gpointer data) {
diff --git a/callback.h b/callback.h
index 3516c50..678c9ba 100644
--- a/callback.h
+++ b/callback.h
@@ -14,7 +14,7 @@ void on_glarea_unrealize (GtkWidget *widget);
 
 void on_axis_value_change (GtkAdjustment *adjustment, gpointer data);
 
-void on_toggle_EXEC_EDIT (GtkWidget *btt_XOR_EXEC_EDIT, GtkWidget *btt_MODEL_RUN_STOP);
+void on_toggle_EXEC_EDIT (GtkWidget *btt_XOR_EXEC_EDIT, gpointer user_data);
 void on_toggle_MODEL_RUN_STOP (GtkWidget *btt_MODEL_RUN_STOP, gpointer data);
 
 void on_open_STATE (GtkWidget *btt_open_STATE, gpointer data);
diff --git a/contain.c b/contain.c
index 61c0c92..7d722e8 100644
--- a/contain.c
+++ b/contain.c
@@ -136,7 +136,6 @@ GtkWidget *get_SPACE_VIEW_box(){
   GtkBox *middle_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 2));
   gtk_box_append (middle_box, GTK_WIDGET (get_image_ALL_SPACE()));
 //  ui_setup_glarea (0, GTK_WIDGET (middle_box));
-  printf("in contain.c   (line 138)   >   ui_setup_glarea (0, GTK_WIDGET (middle_box));   <   commented  2024/06/27\n");
 
   gtk_box_append (middle_box, GTK_WIDGET (gtk_separator_new (GTK_ORIENTATION_VERTICAL)));
   gtk_box_append (middle_box, GTK_WIDGET (right_box));
@@ -150,11 +149,6 @@ GtkWidget *get_SPACE_EDIT_controls_box() {
 }
 
 
-void window_main_child_bottom (GtkBox *page_box){
-    // gtk_box_append (page_box, GTK_WIDGET (get_TIME_EXEC_controls_box()));
-    // gtk_box_append (page_box, GTK_WIDGET (get_SPACE_EDIT_controls_box()));
-}
-
 static void icons_for_fun (GtkHeaderBar *header_bar);
 
 static GtkButton *btt_open_STATE;
@@ -181,14 +175,11 @@ void window_header_bar (GtkWindow *window, char *title){
 
   gpointer no_local_data = NULL;
 
-//  GtkButton *btt_MODEL_RUN_STOP = GTK_BUTTON (gtk_button_new_with_label (" run "));
-//  g_signal_connect (btt_MODEL_RUN_STOP, "clicked", G_CALLBACK (on_toggle_MODEL_RUN_STOP), no_local_data);
-
   GtkButton *btt_XOR_EXEC_EDIT = GTK_BUTTON (gtk_toggle_button_new ());
-  gtk_button_set_icon_name (btt_XOR_EXEC_EDIT, "system-run-symbolic");  //  https://thenounproject.com/icon/train-134324/
+  gtk_button_set_icon_name (btt_XOR_EXEC_EDIT, "system-run-symbolic");
   gtk_button_set_icon_name (btt_XOR_EXEC_EDIT, "process-stop-symbolic");
   gtk_button_set_icon_name (btt_XOR_EXEC_EDIT, "power-profile-balanced-rtl-symbolic");
-  g_signal_connect (btt_XOR_EXEC_EDIT, "clicked", G_CALLBACK (on_toggle_EXEC_EDIT), get_window_child_STATE());  //  btt_MODEL_RUN_STOP);
+  g_signal_connect (btt_XOR_EXEC_EDIT, "clicked", G_CALLBACK (on_toggle_EXEC_EDIT), no_local_data);
 
   GtkWidget *any_Label = GTK_WIDGET (gtk_label_new ("   |   "));
 
@@ -207,7 +198,6 @@ void window_header_bar (GtkWindow *window, char *title){
   gtk_check_button_set_group (GTK_CHECK_BUTTON (btt_open_DATA), group_STATE_RULES_DATA);
 
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_XOR_EXEC_EDIT));
-//  gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_MODEL_RUN_STOP)); //  <<  pas ici !  TODO
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (any_Label));
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_open_STATE));
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_open_RULES));
@@ -215,14 +205,14 @@ void window_header_bar (GtkWindow *window, char *title){
 
 
   icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
-//                                                     https://iconduck.com/sets/carbon-icons   <   pas mal ...
-//  ma préférée : Transport Steam Engine Icon     mais : [ process icon ]  semble un bon choix...
+//                                                   https://iconduck.com/sets/carbon-icons   <   pas mal ...
+//                                                   https://thenounproject.com/icon/train-134324/
+//     ma préférée : Transport Steam Engine Icon     mais : [ process icon ]  semble un bon choix...
 }
 
 void main_window_design (GtkWindow *main_window){
   window_header_bar (main_window,
                      "E coli   (with permission from David S. Goodsell, 2009)");
-  gtk_window_set_child (main_window, GTK_WIDGET (get_window_child_STATE()));
   gtk_check_button_set_active (GTK_CHECK_BUTTON (btt_open_STATE), TRUE);
   gtk_window_present (GTK_WINDOW (main_window));
 }
@@ -240,17 +230,18 @@ void main_window_design (GtkWindow *main_window){
 
 
 GtkWidget *get_window_child_STATE() {
+    if (0) printf("contain.get_window_child_STATE  (line 235)\n");
     GtkBox *page_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 2));
     gtk_box_append (page_box, GTK_WIDGET (get_OBJECTS_and_SITUATIONS()));
     gtk_box_append (page_box, GTK_WIDGET (gtk_separator_new (GTK_ORIENTATION_HORIZONTAL)));
     gtk_box_append (page_box, GTK_WIDGET (get_SPACE_VIEW_box()));
     gtk_box_append (page_box, GTK_WIDGET (gtk_separator_new (GTK_ORIENTATION_HORIZONTAL)));
     gtk_box_append (page_box, GTK_WIDGET (get_TIME_EXEC_controls_box()));
-    //SWITCH_TO (STATE);
     return GTK_WIDGET (page_box);
 }
 
 GtkWidget *get_window_child_RULES(){
+  if (0) printf("contain.get_window_child_RULES  (line 246)\n");
   GtkPaned *H_tree_vs_selected = GTK_PANED (gtk_paned_new (GTK_ORIENTATION_HORIZONTAL));
 //  GtkWidget *arbre_des_règles = gtk_frame_new ("Arbre des règles");
 //  GtkWidget *édition_de_la_règle_sélectionnée_n_1 = gtk_frame_new ("Inspection");
@@ -258,11 +249,11 @@ GtkWidget *get_window_child_RULES(){
   gtk_paned_set_end_child (H_tree_vs_selected, GTK_WIDGET (get_selected_rules_vpaned_new()));
   gtk_paned_set_position (H_tree_vs_selected, 400); //  WARNING : c'est une position "absolue"
   gtk_paned_set_wide_handle (H_tree_vs_selected, TRUE);
-    //SWITCH_TO (RULES);
   return GTK_WIDGET (H_tree_vs_selected);
 }
 
 GtkWidget *get_window_child_DATA (){
+  if (0) printf("contain.get_window_child_DATA  (line 259)\n");
   GtkBox *data_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 32));
 
   GtkWidget* frame_rule_effect = gtk_frame_new ("rule effect\n-----------");
diff --git a/contain.h b/contain.h
index 5be4381..23364c8 100644
--- a/contain.h
+++ b/contain.h
@@ -31,12 +31,11 @@ G_END_DECLS
 */
 
 void main_window_design (GtkWindow *main_window);
-void two_notebooks_in_two_panes (GtkWindow *window);
-GtkWidget *get_selected_rules_vpaned_new();
-GtkFrame *get_frame_with_label();
-void window_main_child_bottom (GtkBox *page_box);
-//void window_main_child (GtkWindow *main_window, int selected_page);
 void set_check_button_active (GtkButton *button, int active);
+void two_notebooks_in_two_panes (GtkWindow *window);
+
+GtkFrame  *get_frame_with_label();
+GtkWidget *get_selected_rules_vpaned_new();
 GtkWidget *get_TIME_EXEC_controls_box();
 GtkWidget *get_SPACE_EDIT_controls_box();
 GtkButton *get_GtkButton (char *btt_name);
diff --git a/main.c b/main.c
index bd2de6e..a5f9b0c 100644
--- a/main.c
+++ b/main.c
@@ -20,5 +20,7 @@ int main (int argc, char **argv)
   status = g_application_run (G_APPLICATION (app), argc, argv);
   g_object_unref (app);
 
+  printf("in contain.get_SPACE_VIEW_box()  (line 138)   >   ui_setup_glarea (0, GTK_WIDGET (middle_box));   <   commented  2024/06/27   >   TODO\n");
+
   return status;
 }