Arthur A. Gleckler scripsit:

> This doesn't seem to be useful enough to warrant inclusion in a general
> library.  Do you have some general class of applications in mind?

It's the rational-number analogue of iota.  It's not as intuitive an
ordering as 1, 2, 3, 4, ... and can't be used for indexing, but it
does traverse the whole (non-negative) set of rational numbers.
The particulars of the ordering are nothing special, except that
they require only a single item of state, the last rational number
generated, and there is a once-and-only-once guarantee.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
I suggest you solicit aid of my followers or learn the difficult art
of mud-breathing.  --Great-Souled Sam