He's redesigning the arrow keys to map to screens instead of mapping to movement from the current screen. The solution to a higher problem space (eg. more than

He's redesigning the arrow keys to map to screens instead of mapping to movement from the current screen. The solution to a higher problem space (eg. more than 4 screens) are additional unique symbols. So if you want 8 screen use the number pad. etc. If you want 26 screens just map a screen to each letter. etc.