In this paper, we extend
Landau’s notion of ‘exchange relations’ so as to make sense for arbitrary
planar algebras, which need not necessarily be generated by its ‘2-boxes’.
We show, as in Landau’s case, that these ‘higher exchange relation planar
algebras’ are necessarily ‘finite dimensional’, and that examples of such planar
algebras are given by all (even possibly reducible) depth two subfactors, as well
as planar algebras associated to subfactors with principal graphs E6 and
E8.