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Most interval-based solvers in the constraint logic programming framework are based on either hull consistency or box consistency (or a variation of these ones) to narrow domains of variables involved in continuous constraint systems. This paper first presents HC4, an algorithm to enforce hull consistency without decomposing complex constraints into(More)
RealPaver is an interval software for modeling and solving nonlinear systems. Reliable approximations of continuous or discrete solution sets are computed using Cartesian products of intervals. Systems are given by sets of equations or inequality constraints over integer and real variables. Moreover, they may have different natures, being square or(More)
Traditional design of numerical software with result verification is based on the assumption that we know the algorithm ¦ ¨ § © £ © that transforms input , and we know the intervals of possible values of the inputs. Many real-life problems go beyond this paradigm. In some cases, we do not have an algorithm ¦ , we only know some relation (constraints)(More)
In this paper we present a framework for the cooperation of symbolic and propagation-based numerical solvers over the real numbers. This cooperation is expressed in terms of xed points of closure operators over a complete lattice of constraint systems. In a second part we instantiate this framework to a particular cooperation scheme, where propagation is(More)
Parameter estimation is the problem of finding the values of the unknowns of a mathematical model for simulating a complex system. A model is generally given by differential equations or systems of equations or inequalities. Interval computations are numerical computations over sets of real numbers. In this paper intervals are used to model uncertainty in(More)
This paper presents the first implementation of COMMA, a new solver independent language for modeling constraint-based problems. The combination of a constraint language with an object-oriented framework represents the base of the core of COMMA. Extension capabilities have also been included with the aim of tackling a wide range of applications from(More)