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, interpret, organize, pre-operational, select, sensorimotor }
Symmetric Difference
$$A \ominus B =$$
{ concrete operational, formal operational, interpret, organize, pre-operational, select, sensorimotor }
Difference
$$A - B =$$
{ concrete operational, formal operational, pre-operational, sensorimotor }
Difference
$$B - A =$$
{ interpret, organize, select }
Cartesian Product
$$A \times B =$$
{ (concrete operational, interpret),
(concrete operational, organize),
(concrete operational, select),
(formal operational, interpret),
(formal operational, organize),
(formal operational, select),
(pre-operational, interpret),
(pre-operational, organize),
(pre-operational, select),
(sensorimotor, interpret),
(sensorimotor, organize),
(sensorimotor, select) }
Cognition