Press the right key for the next slide (or swipe left)
also ...
Press the left key to go backwards (or swipe right)
Press n to toggle whether notes are shown (no equivalent if you don't have a keyboard)
Press m or double tap to see a menu of slides
There is an end, and all ends are this end, and it is near.
∃x ( End(x) ∧ ∀y ( End(y) → x=y ) ∧ Near(x) )