Union
$$A \cup B =$$
{ anagogical, class, family, genus, kingdom, literal, moral, order, phylum, species, typological }
Symmetric Difference
$$A \ominus B =$$
{ anagogical, class, family, genus, kingdom, literal, moral, order, phylum, species, typological }
Difference
$$B - A =$$
{ class, family, genus, kingdom, order, phylum, species }
Cartesian Product
$$A \times B =$$
{ (anagogical, class),
(anagogical, family),
(anagogical, genus),
(anagogical, kingdom),
(anagogical, order),
(anagogical, phylum),
(anagogical, species),
(literal, class),
(literal, family),
(literal, genus),
(literal, kingdom),
(literal, order),
(literal, phylum),
(literal, species),
(moral, class),
(moral, family),
(moral, genus),
(moral, kingdom),
(moral, order),
(moral, phylum),
(moral, species),
(typological, class),
(typological, family),
(typological, genus),
(typological, kingdom),
(typological, order),
(typological, phylum),
(typological, species) }
Allegory in the Middle Ages