* MINLP literature problem
* Kocis and Grossmann, 1988.

VARIABLES
	 x1  
	 x2  
	 y1  
	 y2  
	 y3  
     objval    objective function variable;

FREE VARIABLES    objval;
BINARY VARIABLES y1;
BINARY VARIABLES y2;
BINARY VARIABLES y3;


EQUATIONS
	 f1 Objective function
	 f2  
	 f3  
	 f4  
	 f5  
	 f6 ; 

f1  .. objval =e=2*x1+3*x2+1.5*y1+2*y2-0.5*y3;
f2  .. POWER(x1,2)+y1 =e= 1.25;
f3  .. x2**1.5+1.5*y2 =e= 3;
f4  .. x1+y1 =l= 1.6;
f5  .. 1.333*x2+y2 =l= 3;
f6  .. -y1-y2+y3 =l= 0;

* Bounds
x1.LO = 0; x1.UP = 10;
x2.LO = 0; x2.UP = 10;
y1.LO = 0; y1.UP = 1; 
y2.LO = 0; y2.UP = 1;
y3.LO = 0; y3.UP = 1; 

* Starting point (global solution)
* x1.L = 1.12; x2.L = 1.31;
* y1.L = 0; y2.L = 1; y3.L = 1;

MODEL test /ALL/;
SOLVE test USING MINLP MINIMIZING objval;