`timescale 1ns/1ns module mux4_1( input [1:0]d1,d2,d3,d0, input [1:0]sel, output[1:0]mux_out ); //*************code***********// assign mux_out = (sel<3)?(sel<2)?(sel<1)?2:1:0:3; //*************code***********// endmodule