  Following our recent conjecture to model the phenomenona of
antiferromagnetism and superconductivity by quantum symmetry groups, we discuss
in the present note the choice of the classical symmetry group underlying the
quantum group.
  Keeping in mind the degrees of freedom arising from spin, charge, and lattice
we choose the classical group as SO(7). This choice is also motivated to
accomodate the several competing phases which are or may be present in these
and related materials, such as stripe phase [mesoscopically ordered phase],
Luttinger liquids, nearly antiferromagnetic Fermi liquids, charge-ordered Fermi
liquids, glassy phase, stringy phase and perhaps more. The existence and the
behavior of pseudo-gap and lattice distortion are also an important
consideration.
  We have lumped the charge, spin and lattice-distortion ordering and other
orderings into the psuedogap.
