Looking for a pair of words that compactly express the notion of moving one position forward, and one position backward.
I had thought to use "advance" for the first, as you might say a clock's second hand advances to the next position. But I'm having a hard time coming up with a corresponding word for the opposite direction. I had thought of regress, and recede and some others but they all seem to me to have a connotation of reverting to a previous state instead of simply moving in a rearward direction.
I think "recess" (as in astronomical "procession" / "recession") almost has the right flavor but that meaning of recess is not well known.
Context: This is for naming a pair of subroutines for navigating a list or array in a software system. One can advance one position in the array or
> one position.