let fixpoint s db = if display_fixpoints then begin current_color := next_shade (); fprintf !dot_fmt "%a@." print_subsumed_node s; print_pre (cedge_pre ()^",penwidth=1") !dot_fmt s; List.iter (fun d -> if d <> s.tag then fprintf !dot_fmt "%d -> %d [%s]@." s.tag d cedge_subsume) db end