* NLP literature problem
* Three-hump camelback function, Dixon and Szego (1975)

VARIABLES
	 x  
	 y  
     objval    objective function variable;

FREE VARIABLES    objval;


EQUATIONS
	 f Objective function;

f  .. objval =e=12*POWER(x,2)-(6.3*POWER(x,4))+POWER(x,6)-((6*x)*y)+6*POWER(y,2);

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