Re: Extending my question. Was: The relational model and relational algebra - why did SQL become the industry standard?

Lauri Pietarinen wrote:

Small typo

>-- "set" version
>SELECT AVG'( fx, count )
> FROM (
> SELECT F(x) as fx, count(*) as count
> FROM X
> GROUP BY x )
>

should have been:

SELECT AVG'( fx, count )
  FROM (
    SELECT F(x) as fx, count(*) as count

      FROM X
      GROUP BY F(x) )