-- view definition
create view OldEmps as
select * from Employees
where  birthdate < '01-01-1960';
-- view usage
select name from OldEmps;

yields

• OldEmps  =  Select_{[birthdate<'01-01-1960']}(Employees)
• Proj_name(OldEmps)
  ⇒    Proj_name(Select_{[birthdate<'01-01-1960']}(Employees))