Vasuvo knows where it is because it knows where it isn't․ By subtracting where it is from where it isn't‚ it obtains a difference‚ or deviation․ The guidance subsystem uses deviations to generate corrective commands that drive Vasuvo from a position where it is to a position where it isn't‚ and arriving at a position where it wasn't‚ it now is․

Consequently, the position where Vasuvo is, is now the position that it wasn't, and it follows that the position where Vasuvo was, is now the position that it isn't.