ng the signals in Figure 4.30: (a) at point A; (b) at point B; (c) at point C; (d) at point D and E; (e) at point F Source Coding and Decoding: Making it Digital We can continue the computation of the signals in Figure 4.30 at each and every time instant (and if you try problem 4.7 you'll get just that opportunity). Ultimately, we end up with the values at point C of Figure 4.31(c), the values at point D and E of Figure 4.25(d), and the values at point F of Figure 4.31(e). I don't know if it's clear to you yet from the description above and Figure 4.31, but there's a very easy way (a shortcut) to describing the input-output (x, to x relation- ship of the DM (assuming a = 1). If the input value is larger than the predicted value, then increase the output by 8; if the input value is smaller than the predicted value, then decrease the output by 8. And to help you do this, remember-the predicted value is just the previous output value. A rather neat result is easy to see from the above shortcut. Since you're always increasing or decreasing the output by 8, then if the output is 0 at start-up, the output at any later time is always some k8, where k is an integer. The input-output (x, to xn) relationship can also be resolved using a different shortcut, which uses a graph. Assume a = 1. First, draw the input signal using a dashed line, as I've done in Figure 4.32. Then add little dashes on the x-axis at the sample times. I've also added this into Figure 4.32. Now, at time 0, the predicted value is 0. Because this is smaller than the input at time 0 (see Figure 4.32), increase the output by 8 (which means the output becomes its initial value of 0 plus 8, which is 8). This is drawn in Figure 4.32 using a solid line (see the line labeled 1). Since the output doesn't change until the next sample comes in, draw the output as constant over the time before the next sample arrives. Again, I show this in Figure 4.32 (see the line labeled 2). Now, at sample time 1, a new input sample arrives; we can determine the value of this sa