CREATE FUNCTION ufn_is_word_comprised (set_of_letters VARCHAR(21845), word VARCHAR(21845))
RETURNS TINYINT(1)
BEGIN
    DECLARE wordLength INT;
    DECLARE currentIndex INT;
    DECLARE result TINYINT(1);
    SET wordLength := CHAR_LENGTH(word);
    SET currentIndex := 1;
    SET result := 1;

     WHILE  (currentIndex <= wordLength) DO
        IF(set_of_letters NOT LIKE CONCAT('%',SUBSTR(word,currentIndex,1),'%')) THEN
            SET result:= 0;
        END IF;
        SET currentIndex := currentIndex + 1;
    END WHILE;

    RETURN result;
END