Union
$$A \cup B =$$
{ Anthropology, Economics, Geography, Political science, Psychology, Sociology, earth, fire, metal, water, wood }
Symmetric Difference
$$A \ominus B =$$
{ Anthropology, Economics, Geography, Political science, Psychology, Sociology, earth, fire, metal, water, wood }
Cartesian Product
$$A \times B =$$
{ (Anthropology, earth),
(Anthropology, fire),
(Anthropology, metal),
(Anthropology, water),
(Anthropology, wood),
(Economics, earth),
(Economics, fire),
(Economics, metal),
(Economics, water),
(Economics, wood),
(Geography, earth),
(Geography, fire),
(Geography, metal),
(Geography, water),
(Geography, wood),
(Political science, earth),
(Political science, fire),
(Political science, metal),
(Political science, water),
(Political science, wood),
(Psychology, earth),
(Psychology, fire),
(Psychology, metal),
(Psychology, water),
(Psychology, wood),
(Sociology, earth),
(Sociology, fire),
(Sociology, metal),
(Sociology, water),
(Sociology, wood) }
Wu Xing