Ordered Lists

Are there any relations or functions implemented within powerloom yet
that allow us to actually work with ordered lists?

A list created using listof is specified to be "ordered," but I can't
find any way to make use of this ordering (or even the fact that it's
a list for that matter).  Is there a way to at least define some
simple list primitives such as first-of, rest-of, and append?

Thanks much,
Jeremy Leibs