$*************************************************************
$ Problem of simultaneously determining the optimal structural
$   and operating prameters for a process:  Configuration #1
$
$ M.A. Duran and I.E. Grossmann, "An outer-approximation
$   algorithm for a class of mixed-integer nonlinear programs"
$   Math. Prog. 1986, 36, 307--339
$
$ Example 1
$
$ Optimal Solution = 6.00976
$*************************************************************

DECLARAITON {{
  XVAR {x1,x2,x6};
  YVAR {y1,y2,y3};
  XUBD {2,2,1};
  XLBD {0,0,0};
  BINARY {y1,y2,y3};
}}

MODEL {{
  MIN: 5*y1 + 6*y2 + 8*y3 + 10*x1 - 7*x6
       - 18*log[x2+1] - 19.2*log[x1-x2+1] + 10;
  n1: 0.8*log[x2+1] + 0.96*log[x1-x2+1] - 0.8*x6 =g= 0;
  l2: x2 - x1 =l= 0;
  l3: x2 - 2*y1 =l= 0;
  l4: x1 - x2 - 2*y2 =l= 0;
  n5: log[x2+1] + 1.2*log[x1-x2+1] - x6 - 2*y3 =g= -2;
  ld: y1 + y2 =l= 1;
}}