Union
$$A \cup B =$$
{ condensation, deposition, discovery, freezing, ionization, melting, practical, recombination, sublimation, theoretical, vaporization }
Symmetric Difference
$$A \ominus B =$$
{ condensation, deposition, discovery, freezing, ionization, melting, practical, recombination, sublimation, theoretical, vaporization }
Difference
$$A - B =$$
{ condensation, deposition, freezing, ionization, melting, recombination, sublimation, vaporization }
Cartesian Product
$$A \times B =$$
{ (condensation, discovery),
(condensation, practical),
(condensation, theoretical),
(deposition, discovery),
(deposition, practical),
(deposition, theoretical),
(freezing, discovery),
(freezing, practical),
(freezing, theoretical),
(ionization, discovery),
(ionization, practical),
(ionization, theoretical),
(melting, discovery),
(melting, practical),
(melting, theoretical),
(recombination, discovery),
(recombination, practical),
(recombination, theoretical),
(sublimation, discovery),
(sublimation, practical),
(sublimation, theoretical),
(vaporization, discovery),
(vaporization, practical),
(vaporization, theoretical) }
Charles Sanders Peirce