Equality
$$A \neq B$$
A is not equal to B
Subset
$$A \not\subseteq B$$
A is not a subset of or equal to B
Superset
$$A \not\supseteq B$$
A is not a superset of or equal to B
Intersection
$$A \cap B =$$
{ }
Union
$$A \cup B =$$
{ enclosure, fetishism, hearth, monotheism, mound, polytheism, roof }
Symmetric Difference
$$A \ominus B =$$
{ enclosure, fetishism, hearth, monotheism, mound, polytheism, roof }
Difference
$$A - B =$$
{ fetishism, monotheism, polytheism }
Difference
$$B - A =$$
{ enclosure, hearth, mound, roof }
Cartesian Product
$$A \times B =$$
{ (fetishism, enclosure),
(fetishism, hearth),
(fetishism, mound),
(fetishism, roof),
(monotheism, enclosure),
(monotheism, hearth),
(monotheism, mound),
(monotheism, roof),
(polytheism, enclosure),
(polytheism, hearth),
(polytheism, mound),
(polytheism, roof) }
Law of three stages