-/* Rules numbers. */
-typedef short rule_number_t;
-# define RULE_NUMBER_MAX ((rule_number_t) SHRT_MAX)
-extern rule_number_t nrules;
-# define int_of_rule_number(RNum) ((int) (RNum))
-# define rule_number_as_item_number(RNum) ((item_number_t) (- RNum - 1))
-# define item_number_as_rule_number(INum) ((rule_number_t) (- INum - 1))
+/* Rule numbers. */
+typedef int rule_number;
+#define RULE_NUMBER_MAX INT_MAX
+extern rule_number nrules;