oth a join and a meet of subsets of distinguished atoms. A concept
lattice consists of: a collection of instances, a collection of types,
a collection of formal concepts, an embedding map from instances to
concepts, an embedding map from types to concepts, an order relation on
concepts, and meet and join operators that map subcollections of
concepts to single concepts. The embedding image of an instance is
called an instance concept. The collection of instance concepts is
join-dense: any concept can be expr