module test();
wire signed [7:0] value1;
wire [7:0] value2;
assign value1[3:0] = 4'd2;
assign value2 = abs(value1);
initial begin
#2 $display("%b %b", value1, value2);
if (value2 === 8'bx)
$display("PASSED");
else
$display("FAILED");
end
endmodule