Union
$$A \cup B =$$
{ fable, fairy-tale, folk-tale, interpret, myth, organize, saga, select, stimulus }
Symmetric Difference
$$A \ominus B =$$
{ fable, fairy-tale, folk-tale, interpret, myth, organize, saga, select, stimulus }
Difference
$$A - B =$$
{ interpret, organize, select, stimulus }
Difference
$$B - A =$$
{ fable, fairy-tale, folk-tale, myth, saga }
Cartesian Product
$$A \times B =$$
{ (interpret, fable),
(interpret, fairy-tale),
(interpret, folk-tale),
(interpret, myth),
(interpret, saga),
(organize, fable),
(organize, fairy-tale),
(organize, folk-tale),
(organize, myth),
(organize, saga),
(select, fable),
(select, fairy-tale),
(select, folk-tale),
(select, myth),
(select, saga),
(stimulus, fable),
(stimulus, fairy-tale),
(stimulus, folk-tale),
(stimulus, myth),
(stimulus, saga) }
Optical illusion