Union
$$A \cup B =$$
{ accumulating, agent, form, matter, purpose, reformulating, trans-framing, uni-framing }
Symmetric Difference
$$A \ominus B =$$
{ accumulating, agent, form, matter, purpose, reformulating, trans-framing, uni-framing }
Difference
$$A - B =$$
{ accumulating, reformulating, trans-framing, uni-framing }
Difference
$$B - A =$$
{ agent, form, matter, purpose }
Cartesian Product
$$A \times B =$$
{ (accumulating, agent),
(accumulating, form),
(accumulating, matter),
(accumulating, purpose),
(reformulating, agent),
(reformulating, form),
(reformulating, matter),
(reformulating, purpose),
(trans-framing, agent),
(trans-framing, form),
(trans-framing, matter),
(trans-framing, purpose),
(uni-framing, agent),
(uni-framing, form),
(uni-framing, matter),
(uni-framing, purpose) }
Marvin Minsky