Node:Rationals, Next:Partial Evaluation, Up:Fragments and Bits

The internal data structure for rational numbers is
`rat(`

. `Num`,`Den`)`Den` is always positive, i.e.
the sign of the rational number is the sign of `Num`. Further,
`Num` and `Den` are relative prime. Note that integer `N`
looks like `rat(`

in this representation. You can
control printing of terms with `N`,1)`portray/1`

.