Intervals

Besides finite domains, ECLiPSe also offers continuous domains in the form of numeric intervals.

Ranges: range

The range library simply associates a range with a variable, recording its lower and upper bounds, and checking the range when the variable is instantiated. This is used by the eplex library (interface to LP/MIP solver) and was used by the now obsolete ria interval solver.

Continuous and integral intervals: ic

The ic (interval constraints) library is a integration of an integer finite domain solver and interval reasoning over continuous intervals. It solves equations and inequations between general arithmetic expressions over continuous or integral variables. The expressions can include non-linear functions such as sin and built-in constants such as pi.

In addition to constraints, ic offers search techniques (splitting [22] and squashing [17]) for solving problems involving continuous numeric variables.

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