module myTask_tester;
logic [1:0] sel;
logic a,b;
logic val;

// a = sel[0]
// b = sel[1]
// c = a
// d = b
//                c & 'b & 'a & 'b             c' d a'            ab              cda          db
assign ref_val =  sel[1]&~sel[0]&~a&~b | ~sel[1]&sel[0]&~a  | a&b | sel[1]&sel[0]&a | sel[0]&b;

initial begin
    b = 0;
    forever #10 b = ~b; //d
end

initial begin
    a = 0;
    forever @(negedge b) a = ~a;
end

initial begin
    sel[1] = 0;
    forever @(negedge a) sel[1] = ~sel[1];
end

initial begin
    sel[0] = 0;
    forever @(negedge sel[1]) sel[0] = ~sel[0];
end

initial begin
    repeat(16)
    begin
    #11 $strobe("%d %d %d %d = %d = %d %d", sel[0], sel[1], a, b, ref_val, out, ref_val == out);
    end
    #9 $stop;
end


myTask uut_inst(sel, a, b, out);

endmodule