Union
$$A \cup B =$$
{ Opportunities, Strengths, Threats, Weaknesses, gas, liquid, plasma, solid }
Symmetric Difference
$$A \ominus B =$$
{ Opportunities, Strengths, Threats, Weaknesses, gas, liquid, plasma, solid }
Difference
$$A - B =$$
{ gas, liquid, plasma, solid }
Difference
$$B - A =$$
{ Opportunities, Strengths, Threats, Weaknesses }
Cartesian Product
$$A \times B =$$
{ (gas, Opportunities),
(gas, Strengths),
(gas, Threats),
(gas, Weaknesses),
(liquid, Opportunities),
(liquid, Strengths),
(liquid, Threats),
(liquid, Weaknesses),
(plasma, Opportunities),
(plasma, Strengths),
(plasma, Threats),
(plasma, Weaknesses),
(solid, Opportunities),
(solid, Strengths),
(solid, Threats),
(solid, Weaknesses) }