SET_THEORY_SCHEMA
short long

er	Class
e	Complement
e	Group
f	Identical_sets
f	Identical_to_one_of_set_of_sets
dr	Identifier
e	Intersection
dr	Label
e	Power_set
e	Proper_subset
e	Same_membership
e	Subset
dr	Text
e	Union
e	Union_of_all_members