MOP2 function from Van Valedhuizen's test suite due to Fonseca and Fleming.
makeMOP2Function(dimensions = 2L)
C. M. Fonseca and P. J. Fleming, "Multiobjective genetic algorithms made easy: Selection, sharing and mating restriction," Genetic Algorithms in Engineering Systems: Innovations and Applications, pp. 45-52, Sep. 1995. IEE.