vaddoflow.v

module vaddoflow(
    input [3:0] a,
    input [3:0] b,
    output [6:0] seg_L,
    output oflow);

    wire [4:0] x;

    assign x = a + b;

    vsevenseg u_vsevenseg (
        .x(x[3:0]),
        .seg_L(seg_L)
    );

    assign oflow = x[4];

endmodule