module top; reg pass = 1'b1; wire real rval; real in; assign rval = in + 2; initial begin // $monitor(rval,, in); in = 0; #1 in = 1; #1 in = 2; #1 if (pass) $display("PASSED"); end always @(rval) begin if (rval != in + 2.0) begin $display("FAILED: expected %f, got %f", in + 2.0, rval); pass = 1'b0; end end endmodule