[m-dev.] diff: rat - rational numbers module.

[Andrew Bromage]

G'day all.

Just one small comment.

Vanessa Joy TEAGUE wrote:

> :- func iabs(int) = int.
>
> iabs(X) = ( X < 0 -> -X ; X ).

The predicate int__abs/2 is in the library.  There isn't a function
version, but given that it's so common, there probably should be.
We should also look at deprecating the predicate version (as was done
with the predicate equivalents of pi, e, sqrt, sin, cos etc in math.m).

Of course, this is not an impediment to committing this change. :-)

Cheers,
Andrew Bromage