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
$$A \cup B =$$
{ concrete operational, formal operational, knowledge, position, pre-operational, sensorimotor, status }
Symmetric Difference
$$A \ominus B =$$
{ concrete operational, formal operational, knowledge, position, pre-operational, sensorimotor, status }
Difference
$$A - B =$$
{ concrete operational, formal operational, pre-operational, sensorimotor }
Difference
$$B - A =$$
{ knowledge, position, status }
Cartesian Product
$$A \times B =$$
{ (concrete operational, knowledge),
(concrete operational, position),
(concrete operational, status),
(formal operational, knowledge),
(formal operational, position),
(formal operational, status),
(pre-operational, knowledge),
(pre-operational, position),
(pre-operational, status),
(sensorimotor, knowledge),
(sensorimotor, position),
(sensorimotor, status) }