Function first_try 

fn first_try(
    notice: Notice,
    again: Again,
    pressed: Box<dyn FnOnce(&str) + Send>,
    slot: &Arc<(Mutex<Slot>, Condvar)>,
)

A dose reminder’s first try, on its own thread: recorded before it goes, its outcome left for the tick (told), then as Again says. Sent while the tick waits, in its own words; once the tick stopped waiting, in late words (the doubt first), or not at all (no longer to remind). Answered late, said again in place, the doubt first (shown_late).