Set i /A , B1 , B2 ,  NA , C  , CAL /;


set MINREQ(i) /A , B1 , B2 , C  , CAL /;
* nutrients with minimum requirements
set MAXREQ(i) /A , NA , CAL /;
* nutrients with maximum requirements

set NUTR(i) ;
        NUTR(i) = Yes ;
* nutrients

set FOOD /BEEF , CHK , FISH , HAM , MCH , MTL , SPG , TUR /;
* foods

Parameter n_min /   A      700 ,   C      700 ,
                   B1       0 ,   B2       0 ,
                   NA       0 ,   CAL  16000 /;

Parameter n_max /   A      20000 ,   C           0 ,
                   B1          0 ,   B2          0 ,
                   NA      50000 ,   CAL     24000 /;

Parameter  cost /  BEEF   3.19 ,  CHK    2.59 ,
                   FISH   2.29 ,  HAM    2.89 ,
                   MCH    1.89 ,  MTL    1.99 ,
                   SPG    1.99 ,  TUR    2.49 /;

Parameter  f_min /  BEEF       2 ,  CHK        2 ,
                    FISH       2 ,  HAM        2 ,
                    MCH        2 ,  MTL        2 ,
                    SPG        2 ,  TUR        2 /;

Parameter  f_max /  BEEF        10 ,  CHK         10 ,
                    FISH        10 ,  HAM         10 ,
                    MCH         10 ,  MTL         10 ,
                    SPG         10 ,  TUR         10  /;

Table amt(food,i)
                  A    C   B1   B2    NA   CAL
          BEEF   60   20   10   15   938   295
          CHK     8    0   20   20  2180   770
          FISH    8   10   15   10   945   440
          HAM    40   40   35   10   278   430
          MCH    15   35   15   15  1182   315
          MTL    70   30   15   15   896   400
          SPG    25   50   25   15  1329   370
          TUR    60   20   15   10  1397   450 ;

Variable Buy(FOOD) ,  total_cost

Equation diet_min(i) , diet_max(i) , Def_obj ;

diet_min(i)$MINREQ(i)..
   n_min[i] =l= sum{FOOD, amt[FOOD,i] * Buy[FOOD] } ;
diet_max(i)$MAXREQ(i)..
                sum{FOOD, amt[FOOD,i] * Buy[FOOD] } =l= n_max[i];

Def_obj.. total_cost =e=  sum(FOOD, cost[FOOD] * Buy[FOOD]);

Buy.lo(FOOD) = f_min[FOOD] ;
Buy.up(FOOD) = f_max[FOOD] ;
Buy.l(FOOD)  = f_min[FOOD] ;

Model dietu1 /all/;

Solve dietu1 using nlp minimazing total_cost ;

Display total_cost.l ;