“…The class of n-D systems includes, e. g., repetitive processes [25,27], spatially invariant systems [10,11], positive n-D systems [20], or n-D systems of the fractional order [21], and iterative learning control [10,11,12]. The n-D systems approach is applied in control of ladder circuits [32,31], and in modelling of complex systems [5,6]. Methods for identification of n-D systems are also developed in, for instance, [1,26].…”