Mobius invariant integrable lattice equations associated with KP and 2DTL hierarchies

The integrable lattice equations arising in the context of singular manifol d equations for scalar, multicomponent KP hierarchies and 2D Toda lattice h ierarchy are considered. They generate the corresponding continuous hierarc hy of singular manifold equations, its Backlund transformations and differe nt forms of superposition principles; their distinctive feature is invarian ce under the action of Mobius transformation. Geometric interpretation of t hese discrete equations is given. (C) 1999 Published by Elsevier Science B. V. All rights reserved.