Union
$$A \cup B =$$
{ adenine, cytosine, guanine, interpret, organize, select, stimulus, thymine }
Symmetric Difference
$$A \ominus B =$$
{ adenine, cytosine, guanine, interpret, organize, select, stimulus, thymine }
Difference
$$A - B =$$
{ interpret, organize, select, stimulus }
Difference
$$B - A =$$
{ adenine, cytosine, guanine, thymine }
Cartesian Product
$$A \times B =$$
{ (interpret, adenine),
(interpret, cytosine),
(interpret, guanine),
(interpret, thymine),
(organize, adenine),
(organize, cytosine),
(organize, guanine),
(organize, thymine),
(select, adenine),
(select, cytosine),
(select, guanine),
(select, thymine),
(stimulus, adenine),
(stimulus, cytosine),
(stimulus, guanine),
(stimulus, thymine) }