DECLARE  
A NUMBER :=6; 
B NUMBER :=7; 
BEGIN 
IF (A>B) 
THEN  
DBMS_OUTPUT.PUT_LINE('TRUE'); 
ELSE 
DBMS_OUTPUT.PUT_LINE('FALSE'); 
END IF; 
END;

CREATE OR REPLACE FUNCTION BOL_CHECK ( A IN NUMBER, B IN NUMBER) 
RETURN VARCHAR2 
IS 
BEGIN 
IF ( A>B) THEN  
RETURN 'TRUE'; 
ELSE  
RETURN 'FALSE'; 
END IF; 
END; 

SELECT BOL_CHECK (4,5) FROM DUAL

select CASE WHEN  5>10  THEN  'TRUE' ELSE 'FALSE' END BOLI  from dual