* NLP literature problem
* Reactor network design, Ryoo and Sahinidis (1995)


* Parameters
SCALAR k   / 0.5 /;

SCALAR k1   / 0.09755988 /;

SCALAR k2   / 0.99 /;

SCALAR k3   / 0.0391908 /;

SCALAR k4   / 0.9 /;

VARIABLES
	 CA1  
	 CA2  
	 CB1  
	 CB2  
	 V1  
	 V2  
     objval    objective function variable;

FREE VARIABLES    objval;


EQUATIONS
	 g1  
	 g2  
	 g3  
	 g4  
	 g5  
	 f Objective function;

f  .. objval =e=-CB2;
g1  .. CA1+k1*CA1*V1 =e= 1;
g2  .. CA2-CA1+k2*k1*CA2*V2 =e= 0;
g3  .. CB1+CA1+k3*CB1*V1 =e= 1;
g4  .. CB2-CB1+CA2-CA1+k4*k3*CB2*V2 =e= 0;
g5  .. V1**k+V2**k =l= 4;

* Bounds
CA1.LO = 0; CA1.UP = 1;
CA2.LO = 0; CA2.UP = 1;
CB1.LO = 0; CB1.UP = 1;
CB2.LO = 0; CB2.UP = 1;
V1.LO = 1e-05; V1.UP = 16;
V2.LO = 1e-05; V2.UP = 16;

* Starting point (global solution)
* CA1.L = 0.772; CA2.L = 0.517;
* CB1.L = 0.204; CB2.L = 0.388;
* V1.L = 3.036; V2.L = 5.097;

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