Setup, from Q27 of the paper:
Consider a Society of individuals who may belong to sets called Clubs and Tribes, satisfying: the entire Society is a Tribe; the empty subset is a Tribe; the intersection of any collection of Tribes is a Tribe; the union of any two Tribes is a Tribe; a set is a Club if and only if the set of individuals not in it is a Tribe. The intersection of two Clubs is necessarily
(Same Clubs-and-Tribes setup as the previous question.) The union of a collection of Clubs is necessarily
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