$TITLE ProdPri
* Production Prices Model
* Developed by Ruben Mercado

option NLP=MINOS;
* NOTE TO PC USERS: Remove the asterisk from the above line.
* i.e., on PC this code must be run with the option NLP=MINOS

SCALARS
L1 /0.2/
L2 /0.5/
L3 /0.3/;

VARIABLES
p1
p2
p3
w
r
j  performance index;

EQUATIONS
eqp1
eqp2
eqp3
jd performance index definition;

jd..    j =E= 0;
eqp1.. (0.3*p1 + 0.1*p2 + 0.4*p3) * (1+r) + L1 * w =E= p1;
eqp2.. (0.2*p1 + 0.4*p2 + 0.1*p3) * (1+r) + L2 * w =E= p2;
eqp3.. (0.2*p1 + 0.5*p2 + 0.2*p3) * (1+r) + L3 * w =E= p3;

r.fx = 0;
p1.fx = 1;

MODEL PP1 /all/;
SOLVE PP1 MAXIMIZING J USING NLP;
DISPLAY p1.l, p2.l, p3.l, w.l, r.l;