“…This problem, however, is of crucial importance in nonlinear generalizations to higherorder time-series of the the algorithms presented in this paper. In the nonlinear approach, the number of hyperbolic/circular rotations increases tremendously, making the resulting algorithms practically useless, as it was shown in [20]. Therefore, the nonlinear complexity reduction via consideration of pstationary higher-order time series, spanning p-shift invariant generalized sample-product spaces, can be the subject of a separate paper.…”