what is wrong with this if-statement

I have absolutely no idea what is wrong with this if statement, when I sent values lon = -3 and lat = 7 it should return false but it doesn't.

  if (b < 0 && ((lon > 8 && lon < 0) || (lat > 8 && lat < 0)))
  {

    return false;
  }
  else
  {
    return true ;
  }