Next and previous tick value

Is there a way to get the next and previous tick values?

For instance, if price was 1.34, the next price would be 1.35 and the previous would be 1.33.

However, if price was 16.0. then the next and previous prices would be 15.5 and 16.5.

Just wondering if there's an inbuilt way of finding this info out..

Yes, r_ticks(price, ticks).
So "next" price for selection's back price is r_ticks(back_price, 1) and "previous": r_ticks(back_price, -1)

Thanks Tim