More Smear-Based Variable Selection Heuristics for NCSPs

In this work we attempt to study and discover the principles behind one of the most succesfulvariable selection heuristics in branch-and-prune interval-based solvers: the Smear-based heuristics. Why these heuristics work? Which is their objective?Can we do any better?Based on the principles of the Smear functionand the well-known first-fail principle: "To succeed, try first where you are most likely to fail" we propose several variable selection heuristics. The heuristics are tested and compared to the Smear-based oneson solving twenty nonlinear systems of equations. We report our first results and conclusions.