The square lattice structure of CuO2 layers and the strongly correlated pro
perty of electrons indicate that electrons in cuprates can be determined wi
thin a reduced SO(8) superset of SU(4) superset of SOM(5) group. While, the
spin and charge fluctuations that characterize the low energy magnetic exc
itations are described by a nontrivial SUM(2) x U(1) gauge symmetry. (C) 20
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