Universal scaling with temperature of the resistivity and optical conductivity in the normal state follows from the time-reversal symmetry assumed for the Green function with branch cuts combined with charge-spin separation. The density of states reproduces the extended van Hove singularity in a planar system. The single-particle tunneling conductivity in the superconducting state is nonzero at zero bias voltage, reproducing the pseudogap character of the density of states in the superconducting phase even for the s-wave symmetry of the order parameter. The form of the Ginzburg--Landau functional is also provided.

PACS numbers: 74.72.--h, 71.10.Pm