  Correlation functions of the XXZ model in the massive and massless regimes
are known to satisfy a system of linear equations. The main relations among
them are the difference equations obtained from the qKZ equation by
specializing the variables (\lambda_1,...,\lambda_{2n}) as
(\lambda_1,...,\lambda_n,\lambda_{n}+1,...,\lambda_{1}+1). We call it the
reduced qKZ equation. In this article we construct a special family of
solutions to this system. They can be written as linear combinations of
products of two transcendental functions $\tilde{\omega}, \omega$ with
coefficients being rational functions. We show that correlation functions of
the XXZ model in the massive regime are given by these formulas with an
appropriate choice of $\tilde{\omega}, \omega$. We also present a conjectural
formula in the massless regime.
