Simple maximizing problem using GAMS

*This example uses GAMS to maximize
*y=1+0.5*x+0.25x^2
*y less than x+5
*It uses tables to refer coefficients in the equation

SETS
N index of buses
/N1*N3/ ;

TABLE QUAD(N,*)
coeff
N1 1
N2 0.5
N3 0.25 ;

TABLE LINE(N,*)
coeff
N1 5
N2 1
N3 0 ;

VARIABLES
x
y;

EQUATIONS
ZEq
CEq;

ZEq.. y=e=x*x*QUAD('N3','coeff')+x*QUAD('N2','coeff')+QUAD('N1','coeff') ;
CEq.. y=l=x*x*LINE('N3','coeff')+x*LINE('N2','coeff')+LINE('N1','coeff') ;

MODEL ed /ZEq,CEq/;
SOLVE ed USING NLP MAXIMIZING y;

DISPLAY x.l;
DISPLAY y.l;