Figure 4.34. There are no resistor values given in this circuit. On the left are two input terminals. The bottom one goes to ground and the top one is labeled with a minus sign. The minus terminal connects to the top of R 1 and the other end of R1 is grounded. The minus terminal also connects to the base of Q1. The collector of Q1 goes through R3 to plus 12 volts. The emitter of Q1 goes through R5 then R6, in series, to the emitter of Q2. The base of Q2 goes through R2 to ground. The base of Q2 connects to an input terminal labeled with a plus sign. The other side of this input is grounded. The collector of Q2 goes through R4 to plus 12 volts. The junction of R5 and R6 goes to the collector of Q3. The base of Q3 goes through R7 to ground and also through R8 to minus 12 volts. The emitter of Q3 goes through R9 to minus 12 volts. There are two ways of taking the output from this circuit. Output 1 is shown as connecting between the collectors of Q1 and Q2. Neither side of output 1 is grounded. Output 2 is taken between the collector of Q1 and ground. End verbal description.