text: autocommit off;
  create class c0 (a0 int);
  insert into c0 values (27) to :homey;
  create class c1 (a1 c0 default :homey);
  insert into c1 default values;
  select * from c1;
  alter class c1 add attribute a2 c0 shared :homey;
  select * from c1;
  update c1 set a2 = :homey;
  select * from c1;
  drop c0, c1;
  rollback;
  