xbt_propositional_symbol_t prop_symb = NULL;
prop_symb = xbt_new0(struct xbt_propositional_symbol, 1);
prop_symb->pred = strdup(id);
xbt_propositional_symbol_t prop_symb = NULL;
prop_symb = xbt_new0(struct xbt_propositional_symbol, 1);
prop_symb->pred = strdup(id);