+ RULE_TABLE[R].prec -- the precedence level of R.
+
+ RULE_TABLE[R].precsym -- the symbol-number of the symbol in %prec
+ for R (if any).
+
+ RULE_TABLE[R].assoc -- the associativity of R.
+
+ RULE_TABLE[R].line -- the line where R was defined.
+
+ RULE_TABLE[R].useful -- TRUE iff the rule is used.
+