:- lib(eplex).

:- eplex_instance(prob).  % a. declare an eplex instance

main1(Cost, Vars) :-
        % b. create the problem variables and set their range
        Vars = [A1,A2,A3,B1,B2,B3,C1,C2,C3,D1,D2,D3], 
        prob: (Vars $:: 0.0..1.0Inf),

        % c. post the constraints for the problem to the eplex instance
        prob: (A1 + A2 + A3 $= 21),
        prob: (B1 + B2 + B3 $= 40),
        prob: (C1 + C2 + C3 $= 34),
        prob: (D1 + D2 + D3 $= 10),

        prob: (A1 + B1 + C1 + D1 $=< 50),
        prob: (A2 + B2 + C2 + D2 $=< 30),
        prob: (A3 + B3 + C3 + D3 $=< 40),

        % d. set up the external solver with the objective function
        prob: eplex_solver_setup(min(
                10*A1 + 7*A2 + 200*A3 + 
                 8*B1 + 5*B2 + 10*B3 +
                 5*C1 + 5*C2 +  8*C3 + 
                 9*D1 + 3*D2 +  7*D3)),

        %------------------------------- End of Modelling code

        prob: eplex_solve(Cost).  % e. Solve problem using external solver