diff --git a/callback.c b/callback.c
index 3598ab5..6fc7e26 100644
--- a/callback.c
+++ b/callback.c
@@ -185,14 +185,15 @@ void on_toggle_EXEC_EDIT (GtkWidget *btt_XOR_EXEC_EDIT, GtkWidget *btt_MODEL_RUN
   }
 }
 
-void on_STATE_RULES_DATA_selection (GtkToggleButton *source, gpointer user_data) {
-//  g_print ("Toggle button [%s] is active: %s", gtk_button_get_label (GTK_BUTTON (source)), gtk_toggle_button_get_active (source) ? "Yes" : "No");
+void on_toggle_STATE_RULES_DATA (GtkToggleButton *source, gpointer user_data) {
+  //  https://docs.gtk.org/gtk4/class.ToggleButton.html  <  f..k !   bad code ++
+  // g_print ("Toggle button [%s] is active: %s\n", gtk_button_get_label (GTK_BUTTON (source)), gtk_toggle_button_get_active (source) ? "Yes" : "No");
   int choice = 0;
   switch (choice) {
   case (STATE): get_window_child_STATE (); break;
   case (RULES): get_window_child_STATE (); break;
   case (DATA):  get_window_child_STATE (); break;
-  default : get_window_child_STATE ();
+  default :     get_window_child_STATE ();
   }
 }
 /*
diff --git a/callback.h b/callback.h
index b7bab90..79025dd 100644
--- a/callback.h
+++ b/callback.h
@@ -24,4 +24,4 @@ void on_open_DATA  (GtkWidget *btt_open_DATA,  gpointer data);
 void on_SAVE_CURRENT_MODEL_BEFORE_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data);
 void on_DISCARD_CURRENT_MODEL_AND_START_EDITING (GtkWidget *btt_SAVE_CURRENT_MODEL, gpointer data);
 void on_WRITE_CURRENT_MODEL (GtkWidget *btt_WRITE_CURRENT_MODEL, gpointer data);
-void on_STATE_RULES_DATA_selection (GtkToggleButton *source, gpointer user_data);
+void on_toggle_STATE_RULES_DATA (GtkToggleButton *source, gpointer user_data);
diff --git a/contain.c b/contain.c
index 05e3950..2f49f6e 100644
--- a/contain.c
+++ b/contain.c
@@ -179,27 +179,27 @@ void window_header_bar (GtkWindow *window, char *title) { // https://docs.gtk.or
   GtkCheckButton *group_STATE_RULES_DATA = GTK_CHECK_BUTTON (gtk_check_button_new ());
 
   GtkButton *btt_open_STATE = GTK_BUTTON (gtk_check_button_new_with_label ("state"));
-  g_signal_connect (btt_open_STATE, "toggled", G_CALLBACK (on_STATE_RULES_DATA_selection), NULL);
   gtk_check_button_set_group (GTK_CHECK_BUTTON (btt_open_STATE), group_STATE_RULES_DATA);
+  g_signal_connect (btt_open_STATE, "toggled", G_CALLBACK (on_toggle_STATE_RULES_DATA), NULL);
 
   GtkButton *btt_open_RULES = GTK_BUTTON (gtk_check_button_new_with_label ("rules"));
-  g_signal_connect (btt_open_RULES, "toggled", G_CALLBACK (on_STATE_RULES_DATA_selection), NULL);
   gtk_check_button_set_group (GTK_CHECK_BUTTON (btt_open_RULES), group_STATE_RULES_DATA);
+  g_signal_connect (btt_open_RULES, "toggled", G_CALLBACK (on_toggle_STATE_RULES_DATA), NULL);
 
   GtkButton *btt_open_DATA  = GTK_BUTTON (gtk_check_button_new_with_label ("data analysis"));
-  g_signal_connect (btt_open_DATA,  "toggled", G_CALLBACK (on_STATE_RULES_DATA_selection), NULL);
   gtk_check_button_set_group (GTK_CHECK_BUTTON (btt_open_DATA), group_STATE_RULES_DATA);
+  g_signal_connect (btt_open_DATA,  "toggled", G_CALLBACK (on_toggle_STATE_RULES_DATA), NULL);
 
   gtk_check_button_set_active (GTK_CHECK_BUTTON (btt_open_STATE), TRUE);
 
   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));
+//  gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_MODEL_RUN_STOP));
   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));
   gtk_header_bar_pack_start (GTK_HEADER_BAR (header_bar), GTK_WIDGET (btt_open_DATA));
 
-  icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
+//  icons_for_fun (GTK_HEADER_BAR (header_bar));   //  https://iconduck.com/sets/adwaita-icon-theme
 }
 
 GtkWidget *get_window_child_STATE () {
@@ -214,10 +214,88 @@ GtkWidget *get_window_child_STATE () {
     return GTK_WIDGET (page_box);
 }
 
+GtkWidget *get_window_child_RULES (){
+  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");
+
+  gtk_paned_set_start_child (H_tree_vs_selected, GTK_WIDGET (get_rules_tree_hpaned_new()));
+  gtk_paned_set_end_child (H_tree_vs_selected, GTK_WIDGET (get_selected_rules_vpaned_new()));
+  gtk_paned_set_position (H_tree_vs_selected, 600); //  WARNING : c'est une position "absolue"
+  gtk_paned_set_wide_handle (H_tree_vs_selected, TRUE);
+  // gtk_widget_set_size_request (GTK_WIDGET (H_tree_vs_selected), W, H);  //  inutile... ?
+  return GTK_WIDGET (H_tree_vs_selected);
+}
+
+GtkWidget *get_window_child_DATA (){
+  GtkBox *data_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 16));
+
+  GtkWidget* frame_rule_effect = gtk_frame_new ("rule effect");
+  gtk_frame_set_label_align (GTK_FRAME (frame_rule_effect), 0.5);
+  GtkBox *rule_effect_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 4));
+  gtk_frame_set_child (GTK_FRAME (frame_rule_effect), GTK_WIDGET (rule_effect_box));
+
+  GtkWidget* frame_rule_topic = gtk_frame_new ("rule topic");
+  gtk_frame_set_label_align (GTK_FRAME (frame_rule_topic), 0.5);
+  GtkBox *rule_topic_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 4));
+  gtk_frame_set_child (GTK_FRAME (frame_rule_topic), GTK_WIDGET (rule_topic_box));
+
+  GtkWidget* frame_data_type = gtk_frame_new ("data type");
+  gtk_frame_set_label_align (GTK_FRAME (frame_data_type), 0.5);
+  GtkBox *data_type_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 4));
+  gtk_frame_set_child (GTK_FRAME (frame_data_type), GTK_WIDGET (data_type_box));
+
+  GtkWidget* frame_interpretations = gtk_frame_new ("interpretations");
+  gtk_frame_set_label_align (GTK_FRAME (frame_interpretations), 0.5);
+  GtkBox *interpretations_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 4));
+  gtk_frame_set_child (GTK_FRAME (frame_interpretations), GTK_WIDGET (interpretations_box));
+
+  GtkWidget* frame_discussions = gtk_frame_new ("discussions");
+  gtk_frame_set_label_align (GTK_FRAME (frame_discussions), 0.5);
+  GtkBox *discussions_box = GTK_BOX (gtk_box_new (GTK_ORIENTATION_VERTICAL, 4));
+  gtk_frame_set_child (GTK_FRAME (frame_discussions), GTK_WIDGET (discussions_box));
+
+//gtk_box_append (xxx_box, GTK_WIDGET (gtk_separator_new (GTK_ORIENTATION_HORIZONTAL)));
+
+  gtk_box_append (data_box, GTK_WIDGET (frame_rule_effect));
+  gtk_box_append (data_box, GTK_WIDGET (frame_rule_topic));
+  gtk_box_append (data_box, GTK_WIDGET (frame_data_type));
+  gtk_box_append (data_box, GTK_WIDGET (frame_interpretations));
+  gtk_box_append (data_box, GTK_WIDGET (frame_discussions));
+
+  gtk_box_append (rule_effect_box, gtk_label_new ("*"));
+  gtk_box_append (rule_effect_box, gtk_button_new_with_label ("movement"));
+  gtk_box_append (rule_effect_box, gtk_button_new_with_label ("transport"));
+  gtk_box_append (rule_effect_box, gtk_button_new_with_label ("transformation"));
+
+  gtk_box_append (rule_topic_box, gtk_label_new ("*"));
+  gtk_box_append (rule_topic_box, gtk_button_new_with_label ("objects"));
+  gtk_box_append (rule_topic_box, gtk_button_new_with_label ("situations"));
+
+  gtk_box_append (data_type_box, gtk_label_new ("*"));
+  gtk_box_append (data_type_box, gtk_button_new_with_label ("repartitions"));
+  gtk_box_append (data_type_box, gtk_button_new_with_label ("evolutions"));
+  gtk_box_append (data_type_box, gtk_button_new_with_label ("correlations"));
+
+  gtk_box_append (interpretations_box, gtk_label_new ("*"));
+  gtk_box_append (interpretations_box, gtk_button_new_with_label ("stochastic"));
+  gtk_box_append (interpretations_box, gtk_button_new_with_label ("deterministic"));
+
+  gtk_box_append (discussions_box, gtk_label_new ("*"));
+  gtk_box_append (discussions_box, gtk_button_new_with_label ("context"));
+  gtk_box_append (discussions_box, gtk_button_new_with_label ("methodology"));
+  gtk_box_append (discussions_box, gtk_button_new_with_label ("comparisons"));
+  gtk_box_append (discussions_box, gtk_button_new_with_label ("to improve"));
+  gtk_box_append (discussions_box, gtk_button_new_with_label ("summary"));
+
+  return GTK_WIDGET (data_box);
+}
+
 void main_window_design (GtkWindow *main_window){
-  gtk_window_set_child (main_window, get_window_child_STATE ());
   window_header_bar (main_window,
                      "E coli   (with permission from David S. Goodsell, 2009)");
+  gtk_window_set_child (main_window, get_window_child_STATE ());
   gtk_window_present (GTK_WINDOW (main_window));
 }
 
diff --git a/contain.h b/contain.h
index ac12b63..f2a02f8 100644
--- a/contain.h
+++ b/contain.h
@@ -37,3 +37,5 @@ GtkFrame *get_frame_with_label();
 void window_main_child_bottom (GtkBox *page_box);
 //void window_main_child (GtkWindow *main_window, int selected_page);
 GtkWidget *get_window_child_STATE ();
+GtkWidget *get_window_child_RULES ();
+GtkWidget *get_window_child_DATA ();
diff --git a/display.h b/display.h
index 90cf07a..157190b 100644
--- a/display.h
+++ b/display.h
@@ -21,6 +21,7 @@ GtkWidget *get_image_PHENYLALANINE();
 GtkWidget *get_image_DOPAMINE();
 GtkWidget *get_image_ATP();
 GtkWidget *get_image_AMP();
+GtkWidget *get_rules_tree_hpaned_new();
 
 GtkProgressBar *get_ELAPSED_TIME_ProgressBar();
 GtkBox *get_RUN_STOP_box();