Extending Prolog with Constraint Arithmetic on Real Intervals

Prolog can be extended by a system of constraints on closed intervals to perform declarative relational arithmetic. Imposing constraints on an interval can narrow its range and propagate the narrowing to other intervals related to it by constraint equations or inequalities. Relational interval arithmetic can be used to contain oating point errors and, when combined with Prolog backtracking, to obtain numeric solutions to linear and non-linear rational constraint satisfaction problems over the reals (e.g. n-degree polynomial equations). This technique di ers from other constraint logic programming (CLP) systems like CLP(<) or Prolog-III in that it does not do any symbolic processing.