< = left arrow; moves marble left
> = right arrow; moves marble right
/ = left arrow with hook; moves marble left and then turns into right arrow with hook
\ = right arrow with hook; moves marble right and then turns into left arrow with hook
. = square; kills the marble
? = diamond; moves left marbles left and right marbles right
L = circled L; adds a left marble to the queue
R = circled R; adds a right marble to the queue