Difference Equations Compatible with Trigonometric KZ Differential   Equations
  The trigonometric KZ equations associated with a Lie algebra $\g$ depend on a parameter $\lambda\in\h$ where $\h\subset\g$ is the Cartan subalgebra. We suggest a system of dynamical difference equations with respect to $\lambda$ compatible with the KZ equations. The dynamical equations are constructed in terms of intertwining operators of $\g$-modules. 
V. Tarasov and A. Varchenko