  We report a physical background of the wave function prediction in the
infinite system density matrix renormalization group (DMRG) method, from the
view point of two-dimensional vertex model, a typical lattice model in
statistical mechanics. Singular value decomposition applied to rectangular
corner transfer matrices naturally draws matrix product representation for the
maximal eigenvector of the row-to-row transfer matrix. The wave function
prediction can be expressed as the insertion of an approximate half-column
transfer matrix. This insertion process is in accordance with the scheme
proposed by McCulloch recently.
