//Chapter 4
//Example 4-3
//ProbOnOutputVoltage 
//Page 91,Figure 4-4
clear;clc;
printf ("\n\n The dashed lines drawn on Ei in thew figure locate Vut and Vlt.\n\n At time t=0, Ei is below Vlt, so Vo is at +Vsat. When Ei goes above Vut, at times (a) and (c), Vo switches quickly to -Vsat. \n\nWhen Ei again goes below Vlt, at times (b) and (d), Vo switches quickly to +Vsat. \n\nObserve how positive feedback has eliminated the false crossings ")