diff --git a/callback.c b/callback.c
index 824197d..24f2996 100644
--- a/callback.c
+++ b/callback.c
@@ -44,7 +44,7 @@ void on_bind_user_tree_factory (GtkSignalListItemFactory *factory, GObject* obje
 /******************************************************************************/
 /*                             B U T T O N S                                  */
 /******************************************************************************/
-void ui_toggle_exec_edit (GtkWidget *btt_exec_xor_edit, gpointer data)
+void ui_toggle_exec_edit (GtkWidget *btt_exec_xor_edit, GtkWidget *btt_run_stop_model_exec)
 {
   if (get_exec_edit_mode()) {
     gtk_button_set_icon_name (GTK_BUTTON (btt_exec_xor_edit), "system-run-symbolic");
@@ -53,27 +53,24 @@ void ui_toggle_exec_edit (GtkWidget *btt_exec_xor_edit, gpointer data)
     gtk_button_set_icon_name (GTK_BUTTON (btt_exec_xor_edit), "document-edit-symbolic");
     gtk_button_set_icon_name (GTK_BUTTON (btt_exec_xor_edit), "text-editor-symbolic"); // I hesitate
     set_exec_edit_mode (1);
+
+    if (! get_run_xor_stop_exec()) {  //  il faudra une pop-up window, ici,    TODO
+        // pour prévenir l'utilisateur du risque de perte des données de la simulation en cours
+      set_run_xor_stop_exec (0);
+      gtk_button_set_icon_name (GTK_BUTTON (btt_run_stop_model_exec), "media-playback-pause-symbolic");
+    }
   }
 }
 
 void ui_toggle_model_exec (GtkWidget *btt_run_stop_model_exec, gpointer data)
 {
-  if (get_run_xor_stop_exec()) {
+  if (get_run_xor_stop_exec() && ! get_exec_edit_mode()) {
     gtk_button_set_icon_name (GTK_BUTTON (btt_run_stop_model_exec), "media-playback-start-symbolic");
     set_run_xor_stop_exec (0);
   } else {
     gtk_button_set_icon_name (GTK_BUTTON (btt_run_stop_model_exec), "media-playback-pause-symbolic");
-//  gtk_button_set_icon_name (GTK_BUTTON (btt_run_stop_model_exec), "system-shutdown-symbolic");
-//  I hesitate :  The button should then toggle between activable xor inactivable states
     set_run_xor_stop_exec (1);
   }
 }
 
-void ui_model_exec_depends_on_edition (GtkWidget *btt_run_stop_model_exec, gpointer data)
-{
-  if (get_run_xor_stop_exec() && get_exec_edit_mode()) {
-    gtk_button_set_icon_name (GTK_BUTTON (btt_run_stop_model_exec), "media-playback-start-symbolic");
-//    set_run_xor_stop_exec (0);
-  }
-}
 
diff --git a/callback.h b/callback.h
index 4ba19f2..729a1a2 100644
--- a/callback.h
+++ b/callback.h
@@ -12,7 +12,6 @@ void ui_disable_action (const char *name);
 
 void ui_toggle_exec_edit     (GtkWidget *btt_exec_xor_edit, gpointer data);
 void ui_toggle_model_exec    (GtkWidget *btt_run_stop_model_exec, gpointer data);
-void ui_model_exec_depends_on_edition (GtkWidget *btt_run_stop_model_exec, gpointer data);
 
 void on_quit_action          (GSimpleAction *action, GVariant *parameter, gpointer user_data);
 void on_about_action         (GSimpleAction *action, GVariant *parameter, gpointer user_data);
diff --git a/contain.c b/contain.c
index e1baab8..ee0244a 100644
--- a/contain.c
+++ b/contain.c
@@ -280,25 +280,23 @@ void window_header_bar (GtkWindow *window, char *title){
 //  GtkWidget my_window_controls = *gtk_window_controls_new (GTK_PACK_END); //  _START
 //  gtk_window_controls_set_decoration_layout (GTK_WINDOW_CONTROLS(my_window_controls), NULL); //  const char* layout);
 
+  GtkButton *run_stop_model_exec = GTK_BUTTON (gtk_toggle_button_new ());
+  gtk_button_set_icon_name (run_stop_model_exec, "system-shutdown-symbolic");
+  gtk_button_set_icon_name (run_stop_model_exec, "media-playback-pause-symbolic");
+  gtk_button_set_icon_name (run_stop_model_exec, "media-playback-start-symbolic");
+  g_signal_connect (run_stop_model_exec, "clicked", G_CALLBACK (ui_toggle_model_exec), NULL);
+
   GtkButton *exec_xor_edit = GTK_BUTTON (gtk_toggle_button_new ());
 //  gtk_button_set_icon_name (exec_xor_edit, "system-run-symbolic");
 //  g_signal_connect (exec_xor_edit, "clicked", G_CALLBACK (ui_toggle_run_edit), NULL);
   gtk_button_set_icon_name (exec_xor_edit, "document-edit-symbolic");
   gtk_button_set_icon_name (exec_xor_edit, "text-editor-symbolic");
   gtk_button_set_icon_name (exec_xor_edit, "system-run-symbolic");
-  g_signal_connect (exec_xor_edit, "clicked", G_CALLBACK (ui_toggle_exec_edit), NULL);
-  g_signal_connect (exec_xor_edit, "clicked", G_CALLBACK (ui_model_exec_depends_on_edition), NULL);
+  g_signal_connect (exec_xor_edit, "clicked", G_CALLBACK (ui_toggle_exec_edit), run_stop_model_exec);
+
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (exec_xor_edit));
-
-  gtk_window_set_titlebar (window, header_bar);
-
-  GtkButton *run_stop_model_exec = GTK_BUTTON (gtk_toggle_button_new ());
-  gtk_button_set_icon_name (run_stop_model_exec, "system-shutdown-symbolic");
-  gtk_button_set_icon_name (run_stop_model_exec, "media-playback-pause-symbolic");
-  gtk_button_set_icon_name (run_stop_model_exec, "media-playback-start-symbolic");
-  g_signal_connect (run_stop_model_exec, "clicked", G_CALLBACK (ui_toggle_model_exec), NULL);
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (run_stop_model_exec));
-
+  gtk_window_set_titlebar (window, header_bar);
   icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
 }
 
diff --git a/in_depth.c b/in_depth.c
index 2541917..84e54a0 100644
--- a/in_depth.c
+++ b/in_depth.c
@@ -12,15 +12,9 @@ static int run_stop_val = STOP;
 // ---   EXEC / EDIT   ---------------------------------------------------------
 
 int  get_exec_edit_mode () {return run_edit_mode_val;}
-void set_exec_edit_mode (int prescribed_mode)
-{
-  run_edit_mode_val = prescribed_mode;
-  if (! run_stop_val) {
-    run_stop_val = STOP;
-    //  Là, il faut envoyer un signal   >   signal connect
-    //  set_run_xor_stop_exec (STOP);
-  }
-}
+void set_exec_edit_mode (int prescribed_mode) {run_edit_mode_val = prescribed_mode;}
+  //  if (prescribed_mode == EDIT_MODE && run_stop_val == RUN)   run_stop_val = STOP;
+  //  serait redondant car déjà fait dans le callback ui_toggle_exec_edit()
 
 // ---   RUN / STOP   ----------------------------------------------------------