Untitled

module yMux4to1(z, a0, a1, a2, a3, c);

    parameter SIZE = 2;
    output [SIZE-1:0] z;
    input [SIZE-1:0] a0, a1, a2, a3;
    input [1:0] c;

    wire [SIZE-1:0] zLo, zHi;
    yMux #(SIZE) lo(zLo, a0, a1, c[0]);
    yMux #(SIZE) hi(zHi, a2, a3, c[0]);
    yMux #(SIZE) final(z, zLo, zHi, c[1]);
endmodule