Task 6

SCHEMA task6;
    ENTITY birthdate;
        date: INTEGER;
        month: INTEGER;
        year: INTEGER;
        WHERE
            d: date > 0 AND date < 32
            m: month > 0 AND month < 13
            y: year > 1799 AND year < 2024
    END_ENTITY;
    ENTITY person;
        first_name: STRING;
        last_name: STRING;
        age: INTEGER;
        birth: birthdate;
        WHERE
            a: age >= 0
    END_ENTITY;
END_SCHEMA.