This version of Rel is a maintenance release.
A bug has been fixed in the Rel DBMS. In some cases, the superset operator '>=' did not work correctly. E.g...
WITH (S WHERE CITY = 'London') AS S1,
(SP RENAME (P# AS P#1)) AS SP1:
(P WHERE
((SP1 WHERE P#1=P#) {S#}) >= (S1 {S#}))
...returned bogus results. This has been corrected.
For more information, or to download Rel, see http://dbappbuilder.sourceforge.net/Rel.html