X is a vector/matrix.
steps is an integer indicating how many positions to shift the elements of X. If steps is positive, X is moved to the right for “steps” positions; if steps is negative, X is moved to the left for “steps” positions.
move is the general form of prev and next.
$ x=3 9 5 1 4 9; $ move(x,3); [,,,3,9,5] $ move(x,-2); [5,1,4,9,,]