Discretization of multidimensional submanifolds associated with   Spin-valued spectral problems
  We present a large family of Spin(p,q)-valued discrete spectral problems. The associated discrete nets generated by the so called Sym-Tafel formula are circular nets (i.e., all elementary quadrilaterals are inscribed into circles). These nets are discrete analogues of smooth multidimensional immersions in R^m including isothermic surfaces, Guichard nets, and some other families of orthogonal nets. 
Jan L. Cieslinski