+* Large grammars
+ Are now supported (large token numbers, large grammar size (= sum of
+ the LHS and RHS lengths).
+
+* The initial rule is explicit.
+ Bison used to play hacks with the initial rule, which the user does
+ not write. It is now explicit, and visible in the reports and
+ graphs as rule 0.
+
+* Useless rules are actually removed.
+ Before, Bison reported the useless rules, but, although not used,
+ included them in the parsers.
+