Besides finite domains, ECL^{i}PS^{e} also offers continuous domains in the
form of numeric intervals.
These are also implemented by the *ic* library, which is an integration
of an
integer finite domain solver and interval reasoning over continuous
intervals^{4}.
It solves equations and inequations between
general arithmetic expressions over continuous or integral variables.
The expressions can include non-linear functions such as sin, built-in
constants such as pi. Piecewise linear unary functions are also available.

In addition to constraints, *ic* offers search techniques
(*splitting* [20] and *squashing*
[17])
for solving problems involving continuous numeric variables.

- 4
- The
*ic*library replaces the old*ria*interval solver, and covers most of the functionality of the finite domain solver*fd*