SQL>
SQL> declare
2 v_b BOOLEAN:=false;
3 begin
4 v_b:=extract(year from sysdate)>2000;
5 if v_b then
6 DBMS_OUTPUT.put_line('21st Century!');
7 end if;
8 end;
9 /
21st Century!
PL/SQL procedure successfully completed.
SQL>