/* 

  Balanced meal in Picat.
 
  From the menu.p2 program in Prolog-II+.

  Cf light_meal.pi

  This Picat model was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/


main => go.


go ?=>
  balanced_meal(E,P,D,V),
  println([E,P,D,cal=V]),

  fail,
  
  nl.

go => true.

% " the menu "

% index(-)
hors_d_oeuvre(artichauts_melanie).
hors_d_oeuvre(truffes_sous_le_sel).
hors_d_oeuvre(cresson_oeuf_poche).

% index(-)
meat(grillade_de_boeuf).
meat(poulet_au_tilleul).

% index(-)
fish(bar_aux_algues).
fish(chapon_farci).

% index(-)
dessert(sorbet_aux_poires).
dessert(fraises_chantilly).
dessert(melon_en_surprise).

% " main-course "

main_course(P) ?=> meat(P).
main_course(P) => fish(P).

% " composition of a meal "

meal(E,P,D) => hors_d_oeuvre(E), main_course(P), dessert(D).

% " calorific value of a portion"
% index(-,-)
calories(artichauts_Melanie,150).
calories(cresson_oeuf_poche,202).
calories(truffes_sous_le_sel,212).
calories(grillade_de_boeuf,532).
calories(poulet_au_tilleul,400).
calories(bar_aux_algues,292).
calories(chapon_farci,254).
calories(sorbet_aux_poires,223).
calories(fraises_chantilly,289).
calories(melon_en_surprise,122).

% " calorific value of a meal "
value(E,P,D,V) =>
   calories(E,X),
   calories(P,Y),
   calories(D,Z),
   V = X + Y + Z.

% " balanced meal  "
balanced_meal(E,P,D,V) =>
   meal(E,P,D),
   value(E,P,D,V),
   V < 800.