Consider two 4-bit binary numbers A and B. Bits of A are a3, a2, a1, and a0, and bits of B are b3, b2, b1, and b0. A is greater than B if a3 is 1 and b3 is 0, but if a3 and b3 are the same, then if a2 is 1 and b2 is 0, we can determine that A is greater than B. This evaluation continues until a0 and b0 are considered. If a0 and b0 are equal then A and B are equal. Using discrete gates and Verilog gate primitives build a 4-bit comparator that generates a 1 on its GT output when its 4-bit input A is greater than its B input, and a 1 on its EQ output when A and B are equal. Use the generate statement and other Verilog iterative logic support structures.

Here is a possible implementation of the 4-bit comparator in Verilog:

module comparator (
    input [3:0] A,
    input [3:0] B,
    output reg GT,
    output reg EQ
);

// compare the most significant bit (a3 vs. b3)
always @* begin
    if (A[3] == 1 && B[3] == 0)
        GT = 1;
    else if (A[3] == 0 && B[3] == 1)
        GT = 0;
end

// compare the second most significant bit (a2 vs. b2)
generate
    if (GT == 1) begin
        always @* begin
            if (A[2] == 1 && B[2] == 0)
                GT = 1;
            else if (A[2] == 0 && B[2] == 1)
                GT = 0;
        end
    end
endgenerate

// compare the third most significant bit (a1 vs. b1)
generate
    if (GT == 1) begin
        always @* begin
            if (A[1] == 1 && B[1] == 0)
                GT = 1;
            else if (A[1] == 0 && B[1] == 1)
                GT = 0;
        end
    end
endgenerate

// compare the least significant bit (a0 vs. b0)
generate
    if (GT == 1) begin
        always @* begin
            if (A[0] == 1 && B[0] == 0)
                GT = 1;
            else if (A[0] == 0 && B[0] == 1)
                GT = 0;
            else
                EQ = 1;
        end
    end
endgenerate

endmodule

The `comparator` module takes two 4-bit inputs `A` and `B`, and outputs two 1-bit signals `GT` and `EQ`. The `GT` output is set to 1 when `A` is greater than `B`, and 0 otherwise. The `EQ` output is set to 1 when `A` equals `B`, and 0 otherwise.

The comparison starts by checking the most significant bit (`a3` vs. `b3`) using a simple `if-else` statement. If `a3` is 1 and `b3` is 0, then `GT` is set to 1. If `a3` is 0 and `b3` is 1, then `GT` is set to 0. If `a3` and `b3` are both 0 or both 1, then we need to compare the next bit (`a2` vs. `b2`), and so on.

To handle the iterative nature of the comparison, we use Verilog's `generate` statement to create multiple instances of the `always` block that compares the bits. Each `always` block is conditionally generated based on the current value of `GT`. If `GT` is 0, then we don't need to compare any further bits, so we don't generate any more `always` blocks. If `GT` is 1, then we generate an `always` block to compare the next bit.

Finally, we use another `generate` block to check the least significant bit (`a0` vs. `b0`). If `GT` is still 1 at this point, then `A` is greater than `B`, and we can set `GT` to 1. If `GT` is 0, then `A` is less than `B`, and we don't need to compare any further bits. If `a0` and `b0` are equal, then `A` and `B` are equal, and we set `EQ` to 1.