$************************************************************* $ MINLP Test Problem for OA/ER $ $ C. A. Floudas, "Nonlinear and Mixed-Integer Optimization: $ Fundamentals and Applications", Oxford University Press, $ 1995, p. 161. $ $ Optimal Soluion: -1.9231 $************************************************************* DECLARATION {{ XVAR {a2,a3,b1,b2,b3,c}; YVAR {y1,y2,y3}; BINA {y1,y2,y3}; XLBD {0,0,0,0,0,0}; YSTP {1,1,0}; }} MODEL {{ MIN: -11*c + 7*b1 + b2 + 1.2*b3 + 1.8*a2 + 1.8*a3 + 3.5*y1 + y2 + 1.5*y3; n1: b2 - log[1 + a2] =e= 0 ; n2: b3 - 1.2*log[1+a3] =e= 0 ; l3: c - 0.9*(b1 + b2 + b3) =e= 0; l4: c - y1 =l= 0; l5: b2 - 1.111111*y2 =l= 0; l6: b3 - 1.111111*y3 =l= 0; l7: y2 + y3 =l= 1; }}