Union
$$A \cup B =$$
{ aquarius, arithmetic, astronomy, geometry, leo, music, scorpio, taurus }
Symmetric Difference
$$A \ominus B =$$
{ aquarius, arithmetic, astronomy, geometry, leo, music, scorpio, taurus }
Difference
$$A - B =$$
{ aquarius, leo, scorpio, taurus }
Difference
$$B - A =$$
{ arithmetic, astronomy, geometry, music }
Cartesian Product
$$A \times B =$$
{ (aquarius, arithmetic),
(aquarius, astronomy),
(aquarius, geometry),
(aquarius, music),
(leo, arithmetic),
(leo, astronomy),
(leo, geometry),
(leo, music),
(scorpio, arithmetic),
(scorpio, astronomy),
(scorpio, geometry),
(scorpio, music),
(taurus, arithmetic),
(taurus, astronomy),
(taurus, geometry),
(taurus, music) }
Astrological sign