The top screen is closed: the screen below comes back to front and takes
its resume time. Without a screen below in the chain (no chain, or at the chain
root) the state is unchanged: the previous screen is not known.
The surface trail is not extended: what a return to a
screen below writes there is not known (the screen was already a visit).
The top screen is closed: the screen below comes back to front and takes its resume time. Without a screen below in the chain (no chain, or at the chain root) the state is unchanged: the previous screen is not known. The surface trail is not extended: what a return to a screen below writes there is not known (the screen was already a visit).