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

 

Variables

Names : a, b, c, …
Variables : x, y, z, w, …
Variables are for saying several things about one thing even without specifying which thing it is
NB: `Some x is a horse and x is dead' ain't English.