 The only prerequisite for applying algorithm selection techniques is that there exists (or that there can be constructed) a set of complementary algorithms.Given a portfolio formula_1 of algorithms formula_2, a set of instances formula_3 and a cost metric formula_4, the algorithm selection problem consists of finding a mapping formula_5 from instances formula_6 to algorithms formula_1 such that the cost formula_8 across all instances is optimized.A well-known application of algorithm selection is the Boolean satisfiability problem.