Union
$$A \cup B =$$
{ adenine, bitter, cytosine, guanine, salty, savory, sour, sweet, thymine }
Symmetric Difference
$$A \ominus B =$$
{ adenine, bitter, cytosine, guanine, salty, savory, sour, sweet, thymine }
Difference
$$A - B =$$
{ bitter, salty, savory, sour, sweet }
Difference
$$B - A =$$
{ adenine, cytosine, guanine, thymine }
Cartesian Product
$$A \times B =$$
{ (bitter, adenine),
(bitter, cytosine),
(bitter, guanine),
(bitter, thymine),
(salty, adenine),
(salty, cytosine),
(salty, guanine),
(salty, thymine),
(savory, adenine),
(savory, cytosine),
(savory, guanine),
(savory, thymine),
(sour, adenine),
(sour, cytosine),
(sour, guanine),
(sour, thymine),
(sweet, adenine),
(sweet, cytosine),
(sweet, guanine),
(sweet, thymine) }
Taste