gtk_math_view_set_root(math_view, 0);
gtk_math_view_load_root(math_view, 0);
GUI_unload_document(){  GtkMathView* math_view;  g_return_if_fail(main_area != NULL);  g_return_if_fail(GTK_IS_MATH_VIEW(main_area));  math_view = GTK_MATH_VIEW(main_area);  gtk_math_view_set_root(math_view, 0);  if (doc_name != NULL) g_free(doc_name);  doc_name = NULL;  gtk_statusbar_pop(GTK_STATUSBAR(status_bar), statusbar_context);  gtk_statusbar_push(GTK_STATUSBAR(status_bar), statusbar_context, "");}