Printers publish one paper at once. This resembles cows going across a stream. If the very first cow comes the stream and also does not go across, all staying cows wait in line to go across the stream behind the very first cow. If the very first cow does go across the stream, the various other cows adhere to. When among the various other cows declines throughout the stream, the cows following it quit and also do not go across the stream.