Further arguments passed to the labeling function used
for creating the dimnames of the incidence matrix.
Value
For a \(k\)-ary relation, a \(k\)-dimensional numeric array with
values in the unit interval inheriting from class
relation_incidence whose elements give the memberships of the
corresponding \(k\)-tuples are contained in the relation (for a
crisp relation, a binary (0/1) array with elements indicating whether
the corresponding tuples are contained in the relation or not).