TODO: update

I no longer agree with that item, there are indeed two things to
report: lack of definition, and being useless.  We could have either
one without the other, they are not directly related.

TODO

@@ -1,25 +1,3 @@
-* Bison 3.4
-** bad diagnostics
-%token <val> NUM
-%type  <val> expr term fact
-
-%%
-
-res:  expr { printf ("%d\n", $1); };
-expr: expr '+' term { $$ = $1 + $3; } | term;
-term: NUM | { $$ = 0; };
-
-The second warning about fact is... useless.
-
-$ bison /tmp/bar.y
-/tmp/bar.y:2.24-27: warning: symbol fact is used, but is not defined as a token and has no rules [-Wother]
- %type  <val> expr term fact
-                        ^~~~
-/tmp/bar.y: warning: 1 nonterminal useless in grammar [-Wother]
-/tmp/bar.y:2.24-27: warning: nonterminal useless in grammar: fact [-Wother]
- %type  <val> expr term fact
-                        ^~~~
-
 * Bison 3.5
 ** doc
 I feel its ugly to use the GNU style to declare functions in the doc.  It