This paper is devoted to the study of subfactors arising out of commut
ing squares constructed out of the simplest possible vertex models. Af
ter setting up the necessary general background, we start with two cla
sses of commuting squares and compute the principal graphs of the resu
lting subfactors, one of them being related to the group dual of a sui
table (closed) subgroup of U(N), and the other to the Cayley graph of
a (non-closed) group, module scalars, generated by N elements of U(N).
In the last section, we ''classify'' the commuting squares in dimensi
on 2, and identify the possible resulting principal graphs as A((2n-1)
)((1)), 1 less than or equal to n less than or equal to infinity. (C)
1996 Academic Press, Inc.