实现两个4位二进制码的比较器，输入为两个4位二进制码A3A2A1A0和B3B2B1B0，输出为M(A=B),G(A>B)和L(A<B)。用高低电平开关作为输入，发光二极管作为输出。-Realization of two 4-bit binary code of the comparator input to two 4-bit binary code A3A2A1A0 and B3B2B1B0 output is M (A = B), G (A>　B) and L (A <B)。用高低电平开关作为输入，发光二极管作为输出。