Let ${x0,x1,\u2026,xN\u22121}$ and ${y0,y1,\u2026,yN\u22121}$ be two one-dimensional input sequences consisting of $N$ integer samples each, and with an arithmetic mean of approximately zero. Given these sequences, the pairwise operation produces two output sequences, ${\chi 0,\chi 1,\u2026,\chi N\u22121}$ and ${\varphi 0,\varphi 1,\u2026,\varphi N\u22121}$, consisting of $N$ samples each, and with an arithmetic mean also of approximately zero, as shown in Fig. 2