Wow, I would never had believed there could remain such
typos in the documentation...

> commit bfa74976051cc219ecd4d06de4059abd76fe80ed
> Author: Richard M. Stallman <rms@gnu....>
> Date:   Wed May 19 03:41:36 1993 +0000
>
>     Initial revision

!!!  (that's not the first revision of Bison, but
of bison.texinfo).


We have a lot of doc duplication, especially because of
this "Table of Symbols" node which compiles about everything
from the documentation.  I am not too fond of this, and
I'd be happy to get rid of it (either by generating it
from the rest of the documentation, or by just stating
that "Index" is there for a reason).

nevertheless, we have a (minor) issue:

> $ git grep '@def.*YYERROR'
> doc/bison.texinfo:@deffn {Macro} YYERROR;
> doc/bison.texinfo:@deffn {Statement} {return YYERROR;}
> doc/bison.texinfo:@deffn {Macro} YYERROR

so we have three *different* entries for YYERROR.  Actually,
looking at the index shows uselessly different entries: