Union
$$A \cup B =$$
{ act, check, do, plan, preview, question, read, summarize, test }
Symmetric Difference
$$A \ominus B =$$
{ act, check, do, plan, preview, question, read, summarize, test }
Difference
$$A - B =$$
{ preview, question, read, summarize, test }
Cartesian Product
$$A \times B =$$
{ (preview, act),
(preview, check),
(preview, do),
(preview, plan),
(question, act),
(question, check),
(question, do),
(question, plan),
(read, act),
(read, check),
(read, do),
(read, plan),
(summarize, act),
(summarize, check),
(summarize, do),
(summarize, plan),
(test, act),
(test, check),
(test, do),
(test, plan) }