+XBT_PUBLIC(int) automaton_state_compare(xbt_state_t s1, xbt_state_t s2);
+
+XBT_PUBLIC(int) propositional_symbols_compare_value(const void *s1, const void *s2);
+
+XBT_PUBLIC(int) automaton_transition_compare(const void *t1, const void *t2);
+
+XBT_PUBLIC(int) automaton_label_transition_compare(xbt_exp_label_t l1, xbt_exp_label_t l2);
+
+