Union
$$A \cup B =$$
{ disease, earthquake, efficient (creator), final (function), fire, flood, formal (design), hurricane, lightning, material, meteor, volcano }
Symmetric Difference
$$A \ominus B =$$
{ disease, earthquake, efficient (creator), final (function), fire, flood, formal (design), hurricane, lightning, material, meteor, volcano }
Difference
$$A - B =$$
{ disease, earthquake, fire, flood, hurricane, lightning, meteor, volcano }
Cartesian Product
$$A \times B =$$
{ (disease, efficient (creator)),
(disease, final (function)),
(disease, formal (design)),
(disease, material),
(earthquake, efficient (creator)),
(earthquake, final (function)),
(earthquake, formal (design)),
(earthquake, material),
(fire, efficient (creator)),
(fire, final (function)),
(fire, formal (design)),
(fire, material),
(flood, efficient (creator)),
(flood, final (function)),
(flood, formal (design)),
(flood, material),
(hurricane, efficient (creator)),
(hurricane, final (function)),
(hurricane, formal (design)),
(hurricane, material),
(lightning, efficient (creator)),
(lightning, final (function)),
(lightning, formal (design)),
(lightning, material),
(meteor, efficient (creator)),
(meteor, final (function)),
(meteor, formal (design)),
(meteor, material),
(volcano, efficient (creator)),
(volcano, final (function)),
(volcano, formal (design)),
(volcano, material) }
Bagua