It's available in algorithm not in sequtils (I think I tripped over it too once):
[https://nim-lang.org/docs/algorithm.html#reverse%2CopenArray%5BT%5D%2CNatural%2CNatural](https://nim-lang.org/docs/algorithm.html#reverse%2CopenArray%5BT%5D%2CNatural%2CNatural) [https://nim-lang.org/docs/algorithm.html#reversed,openArray[T](https://nim-lang.org/docs/algorithm.html#reversed,openArray\[T)]
